Missouri River

Missouri River

Overview
The Missouri River flows 2341 miles (3,767.5 km) through the central United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, and is a tributary
Tributary
A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

. It is the longest river in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and drains the third largest area, though only the thirteenth largest by discharge
Discharge (hydrology)
In hydrology, discharge is the volume rate of water flow, including any suspended solids , dissolved chemical species and/or biologic material , which is transported through a given cross-sectional area...

. The Missouri's watershed
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 encompasses most of the American Great Plains
Great Plains
The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...

 east of the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...

, spanning parts of ten U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

s and two Canadian
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 provinces. Cities along the main stem
Main Stem
"Main Stem" is 1942 instrumental by Duke Ellington and His Famous Orchestra. Although recorded in 1942, the single would not be released until 1944 where it was Duke Ellington's last of four number one's on the Harlem Hit Parade. "Main Stem" would also peak at number twenty on the pop chart"Main...

 such as Great Falls
Great Falls, Montana
Great Falls is a city in and the county seat of Cascade County, Montana, United States. The population was 58,505 at the 2010 census. It is the principal city of the Great Falls, Montana Metropolitan Statistical Area, which encompasses all of Cascade County...

, Sioux City
Sioux City, Iowa
Sioux City is a city in Plymouth and Woodbury counties in the western part of the U.S. state of Iowa. The population was 82,684 in the 2010 census, a decline from 85,013 in the 2000 census, which makes it currently the fourth largest city in the state....

, Omaha
Omaha, Nebraska
Omaha is the largest city in the state of Nebraska, United States, and is the county seat of Douglas County. It is located in the Midwestern United States on the Missouri River, about 20 miles north of the mouth of the Platte River...

, Kansas City
Kansas City, Missouri
Kansas City, Missouri is the largest city in the U.S. state of Missouri and is the anchor city of the Kansas City Metropolitan Area, the second largest metropolitan area in Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties...

, and St. Louis
St. Louis, Missouri
St. Louis is an independent city on the eastern border of Missouri, United States. With a population of 319,294, it was the 58th-largest U.S. city at the 2010 U.S. Census. The Greater St...

 are home to many of the basin's people.
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Encyclopedia
The Missouri River flows 2341 miles (3,767.5 km) through the central United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, and is a tributary
Tributary
A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

. It is the longest river in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and drains the third largest area, though only the thirteenth largest by discharge
Discharge (hydrology)
In hydrology, discharge is the volume rate of water flow, including any suspended solids , dissolved chemical species and/or biologic material , which is transported through a given cross-sectional area...

. The Missouri's watershed
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 encompasses most of the American Great Plains
Great Plains
The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...

 east of the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...

, spanning parts of ten U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

s and two Canadian
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 provinces. Cities along the main stem
Main Stem
"Main Stem" is 1942 instrumental by Duke Ellington and His Famous Orchestra. Although recorded in 1942, the single would not be released until 1944 where it was Duke Ellington's last of four number one's on the Harlem Hit Parade. "Main Stem" would also peak at number twenty on the pop chart"Main...

 such as Great Falls
Great Falls, Montana
Great Falls is a city in and the county seat of Cascade County, Montana, United States. The population was 58,505 at the 2010 census. It is the principal city of the Great Falls, Montana Metropolitan Statistical Area, which encompasses all of Cascade County...

, Sioux City
Sioux City, Iowa
Sioux City is a city in Plymouth and Woodbury counties in the western part of the U.S. state of Iowa. The population was 82,684 in the 2010 census, a decline from 85,013 in the 2000 census, which makes it currently the fourth largest city in the state....

, Omaha
Omaha, Nebraska
Omaha is the largest city in the state of Nebraska, United States, and is the county seat of Douglas County. It is located in the Midwestern United States on the Missouri River, about 20 miles north of the mouth of the Platte River...

, Kansas City
Kansas City, Missouri
Kansas City, Missouri is the largest city in the U.S. state of Missouri and is the anchor city of the Kansas City Metropolitan Area, the second largest metropolitan area in Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties...

, and St. Louis
St. Louis, Missouri
St. Louis is an independent city on the eastern border of Missouri, United States. With a population of 319,294, it was the 58th-largest U.S. city at the 2010 U.S. Census. The Greater St...

 are home to many of the basin's people. Measured from its farthest source in southwestern Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

 to the Mississippi's mouth at the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

, it forms part of the world's fourth-longest river system.

As early as 12,000 years ago, prehistoric Paleo-Indians arrived in the Missouri River basin. Prominent Native American
Native Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...

 tribes that lived on the river in immediate pre-Columbian
Pre-Columbian era
The pre-Columbian era incorporates all period subdivisions in the history and prehistory of the Americas before the appearance of significant European influences on the American continents, spanning the time of the original settlement in the Upper Paleolithic period to European colonization during...

 times included the Mandan, Sioux
Sioux
The Sioux are Native American and First Nations people in North America. The term can refer to any ethnic group within the Great Sioux Nation or any of the nation's many language dialects...

, Hidatsa
Hidatsa
The Hidatsa are a Siouan people, a part of the Three Affiliated Tribes. The Hidatsa's autonym is Hiraacá. According to the tribal tradition, the word hiraacá derives from the word "willow"; however, the etymology is not transparent and the similarity to mirahací ‘willows’ inconclusive...

, Osage
Osage Nation
The Osage Nation is a Native American Siouan-language tribe in the United States that originated in the Ohio River valley in present-day Kentucky. After years of war with invading Iroquois, the Osage migrated west of the Mississippi River to their historic lands in present-day Arkansas, Missouri,...

, and Missouria – the latter for whom the river is named. After the 17th century, European and American explorers began to wander the region, and the Missouri basin became part of France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

's Louisiana
Louisiana (New France)
Louisiana or French Louisiana was an administrative district of New France. Under French control from 1682–1763 and 1800–03, the area was named in honor of Louis XIV, by French explorer René-Robert Cavelier, Sieur de la Salle...

; when the United States acquired the territory, the Lewis and Clark Expedition
Lewis and Clark Expedition
The Lewis and Clark Expedition, or ″Corps of Discovery Expedition" was the first transcontinental expedition to the Pacific Coast by the United States. Commissioned by President Thomas Jefferson and led by two Virginia-born veterans of Indian wars in the Ohio Valley, Meriwether Lewis and William...

 traveled the river partly in search of the mythical Northwest Passage
Northwest Passage
The Northwest Passage is a sea route through the Arctic Ocean, along the northern coast of North America via waterways amidst the Canadian Arctic Archipelago, connecting the Atlantic and Pacific Oceans...

. Later in the 19th century, the westward movement of American pioneer
American pioneer
American pioneers are any of the people in American history who migrated west to join in settling and developing new areas. The term especially refers to those who were going to settle any territory which had previously not been settled or developed by European or American society, although the...

s pushed Native Americans out of their traditional lands, leading to wars. The Missouri defined the American frontier in the 19th century, and many prominent westward routes, the Oregon Trail
Oregon Trail
The Oregon Trail is a historic east-west wagon route that connected the Missouri River to valleys in Oregon and locations in between.After 1840 steam-powered riverboats and steamboats traversing up and down the Ohio, Mississippi and Missouri rivers sped settlement and development in the flat...

 among them, followed the river and its tributaries.

Once, the Missouri River was by far the longest river of North America; today however, the Missouri is only slightly longer than the Mississippi. This is due, in large part, to many of the Missouri River's meander
Meander
A meander in general is a bend in a sinuous watercourse. A meander is formed when the moving water in a stream erodes the outer banks and widens its valley. A stream of any volume may assume a meandering course, alternately eroding sediments from the outside of a bend and depositing them on the...

s being cut to facilitate navigation. The lower Missouri valley
Missouri River Valley
The Missouri River Valley outlines the journey of the Missouri River from its headwaters where the Madison, Jefferson and Gallatin Rivers flow together in Montana to its confluence with the Mississippi River in the State of Missouri. At long the valley drains one-sixth of the United States, and is...

 has become a highly productive agricultural and industrial region, and barge
Barge
A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods. Some barges are not self-propelled and need to be towed by tugboats or pushed by towboats...

s shipping grown and manufactured products provide most of today's river commerce. In the 20th century, federal and state agencies including the U.S. Army Corps of Engineers (USACE) heavily dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...

med and channelized the river. Although all of this development has contributed to the region's economic growth, it has taken a toll on the ecology and the water quality of the Missouri.

Course


From the Rockies
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...

 of southwestern Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

, three streams rise to form the headwaters of the Missouri River. The longest begins at Brower's Spring
Brower's Spring
Brower's Spring is a spring in the Centennial Mountains of Montana that is believed to be the ultimate headwaters of the Missouri River.The spring is named for Jacob V. Brower who in 1896 declared it to be the source of the Missouri in The Missouri: Its Utmost Source...

, 9030 feet (2,752.3 m) above sea level, on the northern flank of the Centennial Mountains
Centennial Mountains
The Centennial Mountains are the southernmost sub-range of the Bitterroot Range in the U.S. states of Idaho and Montana. The Centennial Mountains include the Western and Eastern Centennial Mountains...

. Flowing west then north, it flows first in Hell Roaring Creek, then west into the Red Rock
Red Rock River (Montana)
The Red Rock River is a roughly river in southwestern Montana in the United States. Its drainage basin covers over . Its farthest tributary, Hell Roaring Creek, originates in the Beaverhead National Forest near the Montana-Idaho border at Brower's Spring, at an elevation of...

; swinging northeast to become the Beaverhead
Beaverhead River
The Beaverhead River is an approximately -long tributary of the Jefferson River in southwest Montana . It drains an area of roughly . The river's original headwaters, formed by the confluence of the Red Rock River and Horse Prairie Creek, are now flooded under Clark Canyon Reservoir, which also...

, it finally joins with the Big Hole
Big Hole River
The Big Hole River is a tributary of the Jefferson River, approximately 153 miles  long, in southwestern Montana in the United States. It rises in Skinner lake in the Beaverhead National Forest in the Beaverhead Mountains of the Bitterroot Range at the continental divide along the...

 to form the Jefferson
Jefferson River
The Jefferson River is a tributary of the Missouri River, approximately long, in the U.S. state of Montana. The Jefferson River and the Madison River form the official beginning of the Missouri at Missouri Headwaters State Park near Three Forks...

. The Gibbon
Gibbon River
The Gibbon River is a river in Yellowstone National Park, in Wyoming, the United States. It rises in the center of the park at Grebe Lake. It flows for a short distance into Wolf Lake. Below Wolf Lake, the river flows through Virginia Cascades into the Norris valley. It flows near the Norris...

 and Firehole
Firehole River
The Firehole River is one of two major tributaries of the Madison River. It flows north approximately from its source in Madison Lake on the Continental Divide to join the Gibbon River at Madison Junction in Yellowstone National Park...

 rivers flow together to form the Madison River
Madison River
The Madison River is a headwater tributary of the Missouri River, approximately 183 miles long, in Wyoming and Montana. Its confluence with the Jefferson and Gallatin rivers near Three Forks, Montana form the Missouri River....

, similar in size to the Jefferson. Along with the smaller Gallatin River
Gallatin River
The Gallatin River is a tributary of the Missouri River, approximately 120 mi , in the U.S. states of Wyoming and Montana...

, the Madison emerges from Yellowstone National Park
Yellowstone National Park
Yellowstone National Park, established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872, is a national park located primarily in the U.S. state of Wyoming, although it also extends into Montana and Idaho...

 in northwestern Wyoming
Wyoming
Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...

, flowing north and northwest into Montana.

The Missouri River officially starts at the confluence of the Jefferson and Madison in Missouri Headwaters State Park
Missouri Headwaters State Park
Missouri Headwaters State Park is a Montana state park that marks the official start of the Missouri River. It includes the Three Forks of the Missouri National Historic Landmark.It is located near Three Forks, Montana at an elevation of ....

 near the town of Three Forks
Three Forks, Montana
Three Forks is a city in Gallatin County, Montana, United States and is located within the watershed valley system of both the Missouri and Mississippi rivers drainage basins — and is historically considered the birthplace or start of the Missouri River. The population was 1,728 at the 2000 census...

. It flows north through small canyons, shortly being joined by the Gallatin, then passes through Canyon Ferry Lake
Canyon Ferry Lake
thumb|Canyon Ferry LakeCanyon Ferry Lake is a reservoir on the Missouri River near Helena, Montana and Townsend, Montana. It is Montana's third largest body of water, covering 35,181 acres  and 76 miles  of shore . The dam was completed in 1954 and has been used for...

, a reservoir west of the Big Belt Mountains
Big Belt Mountains
The Big Belt Mountains are a section of the Rocky Mountains in the U.S. state of Montana. Situated mainly in the Helena National Forest, the mountains are used for logging and recreation for the surrounding residents. Nearby is Helena, Montana, Canyon Ferry Lake, the Missouri River, Townsend,...

. Issuing from the mountains near Cascade
Cascade, Montana
Cascade is a town in Cascade County, Montana, United States. The population was 819 at the 2000 census. It is part of the 'Great Falls, Montana Metropolitan Statistical Area'.-Geography:...

, the river flows northeast to the city of Great Falls
Great Falls, Montana
Great Falls is a city in and the county seat of Cascade County, Montana, United States. The population was 58,505 at the 2010 census. It is the principal city of the Great Falls, Montana Metropolitan Statistical Area, which encompasses all of Cascade County...

, where it drops over the Great Falls of the Missouri, a series of five substantial waterfalls. The river then winds east through canyons and badlands
Badlands
A badlands is a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded by wind and water. It can resemble malpaís, a terrain of volcanic rock. Canyons, ravines, gullies, hoodoos and other such geological forms are common in badlands. They are often...

 of the Missouri Breaks, meeting the Marias River
Marias River
The Marias River is a tributary of the Missouri River, approximately 210 mi long, in the U.S. state of Montana. It is formed in the Blackfeet Indian Reservation in Glacier County, in northwestern Montana, by the confluence of the Cut Bank Creek and the Two Medicine River...

 then widening into the Fort Peck Lake reservoir a few miles above the confluence with the Musselshell River
Musselshell River
The Musselshell River is a tributary of the Missouri River, long from its origins at the confluence of its North and South Forks near Martinsdale, Montana to its mouth on the Missouri River. It is located east of the Continental divide entirely within Montana in the United States...

. Farther on the river passes through the gates of the Fort Peck Dam
Fort Peck Dam
The Fort Peck Dam is the highest of six major dams along the Missouri River, located in northeast Montana in the United States, near Glasgow, and adjacent to the community of Fort Peck...

, and immediately after that, the Milk River
Milk River (Montana-Alberta)
The Milk River is a tributary of the Missouri River, long, in the United States state of Montana and the Canadian province of Alberta. Rising in the Rocky Mountains, the river drains a sparsely populated, semi-arid watershed of , ending just east of Fort Peck, Montana.-Geography:It is formed in...

 enters from the left.
Flowing eastwards through the plains of eastern Montana
Eastern Montana
Eastern Montana is a loosely-defined region of Montana. Some definitions are more or less inclusive than others, ranging from the most inclusive, which would include the entire part of the state east of the eastern front of the Rocky Mountains...

, the Missouri receives the Poplar River
Poplar River (Saskatchewan-Montana)
The Poplar River is a tributary of the Missouri River, approximately 167 mi long in Saskatchewan in Canada and Montana in the United States....

 from the north before crossing into North Dakota
North Dakota
North Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....

 where the Yellowstone River
Yellowstone River
The Yellowstone River is a tributary of the Missouri River, approximately long, in the western United States. Considered the principal tributary of the upper Missouri, the river and its tributaries drain a wide area stretching from the Rocky Mountains in the vicinity of the Yellowstone National...

, its greatest tributary by volume, joins from the right. At the confluence, the Yellowstone is actually the larger river. The Missouri then meanders east past Williston
Williston, North Dakota
-Demographics:Preliminary data from a 2010 housing study indicates that population has grown by nearly 22 percent over the past decade; the actual increase might be much higher. Williston is in western North Dakota's booming oil patch, and adequate, affordable housing has become a concern. The...

 and into Lake Sakakawea
Lake Sakakawea
Lake Sakakawea is a reservoir in the Missouri River basin in central North Dakota. Named for the Shoshone-Hidatsa woman Sakakawea, it is the third largest man-made lake in the United States, after Lake Mead and Lake Powell. The lake lies in parts of six counties in western North Dakota: Dunn,...

, a reservoir formed by the Garrison Dam
Garrison Dam
Garrison Dam is an earth-fill embankment dam on the Missouri River in central North Dakota. At over two miles in length, it is the fifth-largest earthen dam in the world, constructed by the U.S. Army Corps of Engineers from 1947-53...

, where the river turns south. South of Riverdale
Riverdale, North Dakota
Riverdale is a town in McLean County, North Dakota in the United States. The population was 205 at the 2010 census.Riverdale was the largest of the construction camps that sprang up in 1946 to house workers building the Garrison Dam just to the west...

, the Knife River
Knife River
This article is about the river in North Dakota. For other meanings, see Knife River The Knife River is a tributary of the Missouri River, approximately 120 mi long, in North Dakota in the United States....

 enters from the right. The Missouri continues south to Bismarck
Bismarck, North Dakota
Bismarck is the capital of the U.S. state of North Dakota and the county seat of Burleigh County. It is the second most populous city in North Dakota after Fargo. The city's population was 61,272 at the 2010 census, while its metropolitan population was 108,779...

, the capital of North Dakota, where it receives the Heart River
Heart River
The Heart River is a tributary of the Missouri River, approximately 180 mi long, in western North Dakota in the United States.-Course:...

. It slows into the Lake Oahe
Lake Oahe
Lake Oahe is a large reservoir behind Oahe Dam on the Missouri River beginning in central South Dakota and continuing north into North Dakota in the United States. The lake has an area of and a maximum depth of . By volume, it is the fourth-largest reservoir in the US. Lake Oahe has a length of...

 reservoir just before the Cannonball River
Cannonball River
The Cannonball River is a tributary of the Missouri River, approximately 135 mi long, in southwestern North Dakota in the United States....

 confluence. While it continues south, eventually reaching Oahe Dam
Oahe Dam
The Oahe Dam is a large dam along the Missouri River, just north of Pierre, South Dakota in the United States. It creates Lake Oahe, the fourth largest artificial reservoir in the United States, which stretches up the course of the Missouri to Bismarck, North Dakota. The dam's powerplant provides...

 in South Dakota
South Dakota
South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux American Indian tribes. Once a part of Dakota Territory, South Dakota became a state on November 2, 1889. The state has an area of and an estimated population of just over...

, the Grand
Grand River (South Dakota)
The Grand River is a tributary of the Missouri River in North Dakota and South Dakota in the United States. The length of the combined branch is 110 mi...

, Moreau
Moreau River
The Moreau River is a tributary of the Missouri River, approximately 200 mi long, in South Dakota in the United States.It rises in two forks in northwestern South Dakota, in the Badlands of Harding County. The North Fork rises approximately 10 mi northeast of Crow Buttes...

 and Cheyenne River
Cheyenne River
The Cheyenne River is a tributary of the Missouri River in the U.S. states of Wyoming and South Dakota. It is approximately 295 mi long and drains an area of...

s all join the Missouri from the right.

The Missouri makes a bend to the southeast as it winds through the Great Plains
Great Plains
The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...

, receiving the Niobrara River
Niobrara River
The Niobrara River is a tributary of the Missouri River, approximately long, running through the U.S. states of Wyoming and Nebraska. The river drains one of the most arid sections of the Great Plains, and has a low flow for a river of its length...

 and many smaller tributaries from the right. It then proceeds to form the boundary of South Dakota and Nebraska
Nebraska
Nebraska is a state on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha, on the Missouri River....

, then after being joined by the James River
James River (Dakotas)
The James River is a tributary of the Missouri River, approximately 710 mi long, draning an area of in the U.S. states of North Dakota and South Dakota...

, forms the Iowa
Iowa
Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...

-Nebraska boundary. At Sioux City the Big Sioux River
Big Sioux River
The Big Sioux River is a tributary of the Missouri River, long, in eastern South Dakota and northwestern Iowa in the United States. The United States Board on Geographic Names settled on "Big Sioux River" as the stream's name in 1961....

 comes in from the left. The Missouri flows south to the big city of Omaha
Omaha, Nebraska
Omaha is the largest city in the state of Nebraska, United States, and is the county seat of Douglas County. It is located in the Midwestern United States on the Missouri River, about 20 miles north of the mouth of the Platte River...

 where it receives one of its largest tributaries, the Platte River
Platte River
The Platte River is a major river in the state of Nebraska and is about long. Measured to its farthest source via its tributary the North Platte River, it flows for over . The Platte River is a tributary of the Missouri River, which in turn is a tributary of the Mississippi River which flows to...

. Downstream, it begins to define the Nebraska-Missouri
Missouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...

 border, then flows between Missouri and Kansas
Kansas
Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...

. The Missouri swings east at Kansas City
Kansas City, Missouri
Kansas City, Missouri is the largest city in the U.S. state of Missouri and is the anchor city of the Kansas City Metropolitan Area, the second largest metropolitan area in Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties...

, where the Kansas River
Kansas River
The Kansas River is a river in northeastern Kansas in the United States. It is the southwestern-most part of the Missouri River drainage, which is in turn the northwestern-most portion of the extensive Mississippi River drainage. Its name come from the Kanza people who once inhabited the area...

 enters from the right, and so on into north-central Missouri. It passes south of Columbia
Columbia, Missouri
Columbia is the fifth-largest city in Missouri, and the largest city in Mid-Missouri. With a population of 108,500 as of the 2010 Census, it is the principal municipality of the Columbia Metropolitan Area, a region of 164,283 residents. The city serves as the county seat of Boone County and as the...

 and receives the Osage River
Osage River
The Osage River is a tributary of the Missouri River in central Missouri in the United States. The Osage River is one of the larger rivers in Missouri. The river drains a mostly rural area of . The watershed includes an area of east-central Kansas and a large portion of west-central and central...

, its last major tributary, downstream of Jefferson City
Jefferson City, Missouri
Jefferson City is the capital of the U.S. state of Missouri and the county seat of Cole County. Located in Callaway and Cole counties, it is the principal city of the Jefferson City metropolitan area, which encompasses the entirety of both counties. As of the 2010 census, the population was 43,079...

. The river then rounds the northern side of St. Louis
St. Louis, Missouri
St. Louis is an independent city on the eastern border of Missouri, United States. With a population of 319,294, it was the 58th-largest U.S. city at the 2010 U.S. Census. The Greater St...

 to join the Mississippi River on the border between Missouri and Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

.

Watershed



With a drainage basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 spanning 529350 square miles (1,371,010.2 km²),
the Missouri's catchment encompasses nearly one-sixth of the area of the United States or just over five percent of the continent of North America. The mostly flat, arid basin, comparable to the size of the Canadian province of Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....

, encompasses most of the northern Great Plains
Great Plains
The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...

, stretching over 1500 miles (2,414 km) from the Rocky Mountains in the west to the Mississippi River valley in the east. From north to south it reaches well over 1600 miles (2,574.9 km), from the southern extreme of western Canada in the north to the Arkansas River
Arkansas River
The Arkansas River is a major tributary of the Mississippi River. The Arkansas generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's initial basin starts in the Western United States in Colorado, specifically the Arkansas...

 valley of the south. Compared with the Mississippi River above their confluence, the Missouri is actually much longer (150%) and drains a far greater area (309%). However, the flow of the Missouri at the confluence accounts for only 45 percent of the total amount of water below the meeting of the rivers.
Although vast, the Missouri River watershed is home to only about ten million people, living in all of the U.S. state of Nebraska, parts of the U.S. states of Colorado, Iowa, Kansas, Minnesota, Missouri, Montana, North Dakota, South Dakota, and Wyoming, and small southern portions of the Canadian provinces of Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...

 and Saskatchewan
Saskatchewan
Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....

. The watershed's largest city is Denver, Colorado, with a population of just over 600,000. Significant tributary systems within the basin include the Milk
Milk River (Montana-Alberta)
The Milk River is a tributary of the Missouri River, long, in the United States state of Montana and the Canadian province of Alberta. Rising in the Rocky Mountains, the river drains a sparsely populated, semi-arid watershed of , ending just east of Fort Peck, Montana.-Geography:It is formed in...

 and Yellowstone
Yellowstone River
The Yellowstone River is a tributary of the Missouri River, approximately long, in the western United States. Considered the principal tributary of the upper Missouri, the river and its tributaries drain a wide area stretching from the Rocky Mountains in the vicinity of the Yellowstone National...

 in the northwest, the James
James River (Dakotas)
The James River is a tributary of the Missouri River, approximately 710 mi long, draning an area of in the U.S. states of North Dakota and South Dakota...

 and Osage
Osage River
The Osage River is a tributary of the Missouri River in central Missouri in the United States. The Osage River is one of the larger rivers in Missouri. The river drains a mostly rural area of . The watershed includes an area of east-central Kansas and a large portion of west-central and central...

 of the east, and the Platte
Platte River
The Platte River is a major river in the state of Nebraska and is about long. Measured to its farthest source via its tributary the North Platte River, it flows for over . The Platte River is a tributary of the Missouri River, which in turn is a tributary of the Mississippi River which flows to...

 and Kansas
Kansas River
The Kansas River is a river in northeastern Kansas in the United States. It is the southwestern-most part of the Missouri River drainage, which is in turn the northwestern-most portion of the extensive Mississippi River drainage. Its name come from the Kanza people who once inhabited the area...

-Republican
Republican River
The Republican River is a river in the central Great Plains of North America, flowing through the U.S. states of Nebraska and Kansas.-Geography:...

/Smoky Hill
Smoky Hill River
The Smoky Hill River is a river in the central Great Plains of North America, running through the U.S. states of Colorado and Kansas.-Names:The Smoky Hill gets its name from the Smoky Hills region of north-central Kansas through which it flows...

 drainages of the southwestern plains. The Platte is the longest tributary, but the Yellowstone River is the largest tributary by discharge (in fact the Yellowstone's flow is about 13800 cuft/s while the Platte averages a comparatively mere 7000 cuft/s).

Elevations in the watershed vary widely from just over 400 feet (121.9 m) at the Missouri's mouth to the high-altitude prairie of South Park in central Colorado. The river itself drops from about 9000 feet (2,743.2 m) in elevation at Brower's Spring, the farthest source. Although the plains of the watershed have extremely little local vertical relief, there is a definite slope from west to east; the land is roughly 3000 feet (914.4 m) above sea level at the base of the Rockies, but less than 500 feet (152.4 m) at the border of the Mississippi valley.

As one of the continent's most important rivers, the Missouri's drainage basin borders on many other major watersheds of the United States and Canada. The Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...

 and Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...

 systems drain the area west of the Rocky Mountains; however, in Wyoming, between the Missouri and Colorado watersheds there is an endorheic drainage called the Great Divide Basin
Great Divide Basin
The Great Divide Basin is a drainage basin of the Continental Divide of the Americas. The basin is between the Green River watershed on the west and the Medicine Bow River watershed on the east . From the northwest, the basin begins in the "Wind River Range .....

, that is sometimes counted within the Missouri basin. On the north low divides separate it from the Saskatchewan
Saskatchewan River
The Saskatchewan River is a major river in Canada, approximately long, flowing roughly eastward across Saskatchewan and Manitoba to empty into Lake Winnipeg...

 and Red River of the North
Red River of the North
The Red River is a North American river. Originating at the confluence of the Bois de Sioux and Otter Tail rivers in the United States, it flows northward through the Red River Valley and forms the border between the U.S. states of Minnesota and North Dakota before continuing into Manitoba, Canada...

, as well as several large endorheic areas in southern Alberta, Saskatchewan and northeastern North Dakota. On the east it is bordered by the upper Mississippi River
Upper Mississippi River
The Upper Mississippi River is the portion of the Mississippi River upstream of Cairo, Illinois, United States. From the headwaters at Lake Itasca, Minnesota, the river flows approximately 2000 kilometers to Cairo, where it is joined by the Ohio River to form the Lower Mississippi...

 and its western tributaries, and to the south by the Arkansas
Arkansas River
The Arkansas River is a major tributary of the Mississippi River. The Arkansas generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's initial basin starts in the Western United States in Colorado, specifically the Arkansas...

 and White
White River (Arkansas)
The White River is a 722-mile long river that flows through the U.S. states of Arkansas and Missouri.-Course:The source of the White River is in the Boston Mountains of northwest Arkansas, in the Ozark-St. Francis National Forest southeast of Fayetteville...

 watersheds.

Major tributaries



Over 95 major tributaries and hundreds of smaller ones feed the Missouri River, with most of the larger ones coming in as the river draws close to the mouth. The largest by discharge are the Yellowstone, Osage, Kansas and Platte. On the other end of the scale is the tiny Roe River
Roe River
The Roe River runs between Giant Springs and the Missouri River in Great Falls, Montana, United States. The Roe River is only 201 feet at its longest constant point....

 in Montana, which at 201 feet (61.3 m) long is commonly held to be the world's shortest river. Tributaries of the Missouri River over 40 miles (64.4 km) long are listed going downstream also noting the state in which they enter.

  • Jefferson River
    Jefferson River
    The Jefferson River is a tributary of the Missouri River, approximately long, in the U.S. state of Montana. The Jefferson River and the Madison River form the official beginning of the Missouri at Missouri Headwaters State Park near Three Forks...

     (MT)
  • Madison River
    Madison River
    The Madison River is a headwater tributary of the Missouri River, approximately 183 miles long, in Wyoming and Montana. Its confluence with the Jefferson and Gallatin rivers near Three Forks, Montana form the Missouri River....

     (MT)
  • Gallatin River
    Gallatin River
    The Gallatin River is a tributary of the Missouri River, approximately 120 mi , in the U.S. states of Wyoming and Montana...

     (MT)
  • Sixteen Mile Creek (MT)
  • Dearborn River
    Dearborn River
    The Dearborn River is a tributary of the Missouri River, approximately 70 mi long, in western Montana in the United States. It rises in the Lewis and Clark National Forest, near Scapegoat Mountain in the Lewis and Clark Range of the Rocky Mountains at the continental divide, in western Lewis...

     (MT)
  • Smith River
    Smith River (Montana)
    Smith River is a tributary of the Missouri River, in central Montana, in the United States. It rises in southern Meagher County in the Castle Mountains and flows northwest in the valley between the Big Belt and Little Belt mountains, past White Sulphure Springs and past Smith River State Park...

     (MT)
  • Sun River
    Sun River
    The Sun River is a tributary of the Missouri River in the Great Plains, approximately 130 mi long, in Montana in the United States....

     (MT)
  • Belt Creek
    Belt Creek (Montana)
    Belt Creek is a tributary, approximately 80 mi long, of the Missouri River in western Montana in the United States.It originates in the Lewis and Clark National Forest north of Big Baldy Mountain, in the Little Belt Mountains in western Judith Basin County...

     (MT)
  • Marias River
    Marias River
    The Marias River is a tributary of the Missouri River, approximately 210 mi long, in the U.S. state of Montana. It is formed in the Blackfeet Indian Reservation in Glacier County, in northwestern Montana, by the confluence of the Cut Bank Creek and the Two Medicine River...

     (MT)
  • Arrow Creek
    Arrow Creek (Montana)
    Arrow Creek is a tributary of the Missouri River, approximately 45 miles long, in Montana in the United States. It rises in the Lewis and Clark National Forest near Highwood Baldy in the Highwood Mountains in southern Chouteau County...

     (MT)
  • Judith River
    Judith River
    The Judith River is a tributary of the Missouri River, approximately 124 mi long, running through central Montana and the United States. It rises in the Little Belt Mountains and flows northeast past Utica and Hobson...

     (MT)
  • Cow Creek
    Cow Creek (Montana)
    Cow Creek is a tributary of the Missouri River, approximately long, in north central Montana in the United States. Cow Creek rises in the southern foothills of the Bear Paw Mountains in western Blaine County and flows east and then south, joining the Missouri approximately air miles northeast of...

     (MT)
  • Musselshell River
    Musselshell River
    The Musselshell River is a tributary of the Missouri River, long from its origins at the confluence of its North and South Forks near Martinsdale, Montana to its mouth on the Missouri River. It is located east of the Continental divide entirely within Montana in the United States...

     (MT)
  • Milk River
    Milk River (Montana-Alberta)
    The Milk River is a tributary of the Missouri River, long, in the United States state of Montana and the Canadian province of Alberta. Rising in the Rocky Mountains, the river drains a sparsely populated, semi-arid watershed of , ending just east of Fort Peck, Montana.-Geography:It is formed in...

     (MT)
  • Redwater River
    Redwater River
    The Redwater River is a tributary of the Missouri River, approximately 110 mi , in eastern Montana in the United States.It rises in on the northern slope of the Big Sheep Mountains, in northwestern Prairie County, and flows northeast across the plains past Brockway and Circle and joins the...

     (MT)
  • Poplar River (MT)
  • Big Muddy Creek (MT)
  • Yellowstone River
    Yellowstone River
    The Yellowstone River is a tributary of the Missouri River, approximately long, in the western United States. Considered the principal tributary of the upper Missouri, the river and its tributaries drain a wide area stretching from the Rocky Mountains in the vicinity of the Yellowstone National...

     (ND)

  • Little Muddy Creek
    Little Muddy Creek (North Dakota)
    Little Muddy Creek is a tributary of the Missouri River, approximately 45 mi long, in northwestern North Dakota in the United States....

     (ND)
  • Tobacco Garden Creek
    Tobacco Garden Creek
    Tobacco Garden Creek is a tributary of the Missouri River, approximately 30 mi long, in northwestern North Dakota in the United States. It rises in the badlands south of the Missouri in McKenzie County, and flows SE, then NNE. It joins the Missouri in Tobacco Garden Bay, an inlet of Lake...

     (ND)
  • Little Missouri River
    Little Missouri River (North Dakota)
    The Little Missouri River is a tributary of the Missouri River, 560 mi long, in the northern Great Plains of the United States. Rising in northeastern Wyoming, in western Crook County about west of Devil's Tower, it flows northeastward, across a corner of southeastern Montana, and into South Dakota...

     (ND)
  • Knife River
    Knife River
    This article is about the river in North Dakota. For other meanings, see Knife River The Knife River is a tributary of the Missouri River, approximately 120 mi long, in North Dakota in the United States....

     (ND)
  • Heart River
    Heart River
    The Heart River is a tributary of the Missouri River, approximately 180 mi long, in western North Dakota in the United States.-Course:...

     (ND)
  • Cannonball River
    Cannonball River
    The Cannonball River is a tributary of the Missouri River, approximately 135 mi long, in southwestern North Dakota in the United States....

     (ND)
  • Grand River
    Grand River (South Dakota)
    The Grand River is a tributary of the Missouri River in North Dakota and South Dakota in the United States. The length of the combined branch is 110 mi...

     (ND)
  • Moreau River
    Moreau River
    The Moreau River is a tributary of the Missouri River, approximately 200 mi long, in South Dakota in the United States.It rises in two forks in northwestern South Dakota, in the Badlands of Harding County. The North Fork rises approximately 10 mi northeast of Crow Buttes...

     (SD)
  • Cheyenne River
    Cheyenne River
    The Cheyenne River is a tributary of the Missouri River in the U.S. states of Wyoming and South Dakota. It is approximately 295 mi long and drains an area of...

     (SD)
  • Bad River
    Bad River (South Dakota)
    The Bad River is a tributary of the Missouri River, approximately long, in central South Dakota in the United States.The river is formed at Philip, South Dakota, by the confluence of its North and South forks...

     (SD)
  • Niobrara River
    Niobrara River
    The Niobrara River is a tributary of the Missouri River, approximately long, running through the U.S. states of Wyoming and Nebraska. The river drains one of the most arid sections of the Great Plains, and has a low flow for a river of its length...

     (NE)
  • James River
    James River (Dakotas)
    The James River is a tributary of the Missouri River, approximately 710 mi long, draning an area of in the U.S. states of North Dakota and South Dakota...

     (SD)
  • Vermillion River
    Vermillion River (South Dakota)
    The Vermillion River is a tributary of the Missouri River, long, in eastern South Dakota in the United States.It is formed by the confluence of the East Fork Vermillion River and West Fork Vermillion River. The East Fork, approximately long, rises in Lake Whitewood in Kingsbury County on the...

     (SD)
  • White River
    White River (South Dakota)
    The White River is a Missouri River tributary that flows through the U.S. states of Nebraska and South Dakota. The name stems from the water's white-gray color, a function of eroded sand, clay, and volcanic ash carried by the river...

     (SD)
  • Big Sioux River
    Big Sioux River
    The Big Sioux River is a tributary of the Missouri River, long, in eastern South Dakota and northwestern Iowa in the United States. The United States Board on Geographic Names settled on "Big Sioux River" as the stream's name in 1961....

     (SD, IA)
  • Perry Creek
    Perry Creek
    Perry Creek is a tributary of the Missouri River in the state of Iowa. It rises in central Plymouth County and flows generally to the south-by-southwest, crossing the Woodbury County line at the city limits of Sioux City, north of Briar Cliff University and the Sioux City Country Club...

     (IA)
  • Floyd River
    Floyd River
    The Floyd River is a tributary of the Missouri River, long, in northwestern Iowa in the United States. It enters the Missouri at Sioux City, and is named for Charles Floyd, a member of the Lewis and Clark Expedition.-Course:...

     (IA)

  • Little Sioux River
    Little Sioux River
    The Little Sioux is a river in the United States. It rises in southwest Minnesota near the Iowa border, and continues to flow southwest for across northwest Iowa into the Missouri River at Little Sioux. The Little Sioux River was known as Eaneah-waudepon or "Stone River" to the Sioux Indians...

     (IA)
  • Soldier River
    Soldier River
    The Soldier River is a tributary of the Missouri River, about long, in western Iowa in the United States. Several portions of the river's course have been straightened and channelized....

     (IA)
  • Boyer River
    Boyer River
    The Boyer River is a tributary of the Missouri River, long, in western Iowa in the United States. Most reaches of the river's course have been straightened and channelized....

     (IA)
  • Mosquito Creek
    Mosquito Creek (Iowa)
    Mosquito Creek, about 60 mi. long, is a tributary of the Missouri River in southwest Iowa in the United States. It rises near Earling, in Shelby County, and flows in a generally southwesterly direction, meeting the Missouri approximately 5 mi. downstream of Council Bluffs.-External links:*...

     (IA)
  • Platte River
    Platte River
    The Platte River is a major river in the state of Nebraska and is about long. Measured to its farthest source via its tributary the North Platte River, it flows for over . The Platte River is a tributary of the Missouri River, which in turn is a tributary of the Mississippi River which flows to...

     (NE)
  • Little Nemaha River
    Nemaha River basin
    The Nemaha River basin includes the areas of the U.S. state of Nebraska below the Platte River basin that drain directly into the Missouri River. The major streams of the drainage include Weeping Water Creek, Muddy Creek, Little Nemaha River, and Big Nemaha River...

     (NE)
  • Big Nemaha River
    Nemaha River basin
    The Nemaha River basin includes the areas of the U.S. state of Nebraska below the Platte River basin that drain directly into the Missouri River. The major streams of the drainage include Weeping Water Creek, Muddy Creek, Little Nemaha River, and Big Nemaha River...

     (NE)
  • Nishnabotna River
    Nishnabotna River
    The Nishnabotna River is a tributary of the Missouri River in southwestern Iowa, northwestern Missouri and southeastern Nebraska in the United States. It flows for most of its length as two parallel streams in Iowa, the East Nishnabotna River and the West Nishnabotna River...

     (IA)
  • Nodaway River
    Nodaway River
    The Nodaway River is a river in southwest Iowa and northwest Missouri.-Etymology:The river's name first appears in the journal of Lewis and Clark, who camped at the mouth of the river on July 8, 1804, but who provide no derivation of the name. There exist several proposed etymologies...

     (MO)
  • Platte River
    Platte River (Missouri)
    The Platte River is a tributary of the Missouri River, about long, in southwestern Iowa and northwestern Missouri in the United States. It is sometimes known as the Little Platte River to distinguish it from the larger Platte River, also a tributary of the Missouri, in nearby Nebraska; the Platte...

     (MO)
  • Kansas River
    Kansas River
    The Kansas River is a river in northeastern Kansas in the United States. It is the southwestern-most part of the Missouri River drainage, which is in turn the northwestern-most portion of the extensive Mississippi River drainage. Its name come from the Kanza people who once inhabited the area...

     (KS)
  • Blue River
    Blue River (Missouri)
    The Blue River is a stream that flows through Johnson County, Kansas and Jackson County, Missouri in the Kansas City Metropolitan Area. The river rises in Johnson County near the border of the states of Kansas and Missouri...

     (MO)
  • Grand River
    Grand River (Missouri)
    The Grand River is a river that stretches from northernmost tributary origins between Creston and Winterset in Iowa approximately to its mouth on the Missouri River near Brunswick, Missouri....

     (MO)
  • Chariton River
    Chariton River
    The Chariton River is a tributary to the Missouri River in southeast Iowa and northeast Missouri.It has been called Missouri's "Grand Divide" because streams west of the Chariton flow into the Missouri and streams east of it flow into the Mississippi River....

     (MO)
  • Lamine River
    Lamine River
    The Lamine River is a tributary of the Missouri River in central Missouri in the United States. It is formed in northern Morgan County about southeast of Otterville by the confluence of Flat Creek and Richland Creek, and flows generally northwardly through Cooper and Pettis counties...

     (MO)
  • Osage River
    Osage River
    The Osage River is a tributary of the Missouri River in central Missouri in the United States. The Osage River is one of the larger rivers in Missouri. The river drains a mostly rural area of . The watershed includes an area of east-central Kansas and a large portion of west-central and central...

     (MO)
  • Gasconade River
    Gasconade River
    The Gasconade River is about long and is located in central and south-central Missouri in the United States.The Gasconade River begins in the Ozarks southeast of Hartville in Wright County and flows generally north-northeastwardly through Wright, Laclede, Pulaski, Phelps, Maries, Osage and...

     (MO)

The longest tributaries of the Missouri, as measured from the mouth to the farthest source (regardless of naming changes), are listed in the below table in addition to their respective drainage basins and discharges.
Tributary Length Drainage basin Discharge
Platte River
Platte River
The Platte River is a major river in the state of Nebraska and is about long. Measured to its farthest source via its tributary the North Platte River, it flows for over . The Platte River is a tributary of the Missouri River, which in turn is a tributary of the Mississippi River which flows to...

A1,025 mi
(1,650 km)
A84,910 mi2
(219,900 km2)
D7,037 cuft/s
(199 m3/s)
Kansas River
Kansas River
The Kansas River is a river in northeastern Kansas in the United States. It is the southwestern-most part of the Missouri River drainage, which is in turn the northwestern-most portion of the extensive Mississippi River drainage. Its name come from the Kanza people who once inhabited the area...

B779 mi
(1,250 km)
C59,500 mi2
(154,100 km2)
C7,367 cuft/s
(209 m3/s)
Milk River
Milk River (Montana-Alberta)
The Milk River is a tributary of the Missouri River, long, in the United States state of Montana and the Canadian province of Alberta. Rising in the Rocky Mountains, the river drains a sparsely populated, semi-arid watershed of , ending just east of Fort Peck, Montana.-Geography:It is formed in...

C729 mi
(1,170 km)
F15,300 mi2
(39,630 km2)
H618 cuft/s
(17.5 m3/s)
James River
James River (Dakotas)
The James River is a tributary of the Missouri River, approximately 710 mi long, draning an area of in the U.S. states of North Dakota and South Dakota...

D710 mi
(1,140 km)
E21,500 mi2
(55,680 km2)
G646 cuft/s
(18.3 m3/s)
Yellowstone River
Yellowstone River
The Yellowstone River is a tributary of the Missouri River, approximately long, in the western United States. Considered the principal tributary of the upper Missouri, the river and its tributaries drain a wide area stretching from the Rocky Mountains in the vicinity of the Yellowstone National...

E702 mi
(1,130 km)
B70,000 mi2
(181,300 km2)
A13,800 cuft/s
(391 m3/s)
White River
White River (South Dakota)
The White River is a Missouri River tributary that flows through the U.S. states of Nebraska and South Dakota. The name stems from the water's white-gray color, a function of eroded sand, clay, and volcanic ash carried by the river...

F580 mi
(933 km)
I10,200 mi2
(26,420 km2)
I570 cuft/s
(16.1 m3/s)
Little Missouri River
Little Missouri River (North Dakota)
The Little Missouri River is a tributary of the Missouri River, 560 mi long, in the northern Great Plains of the United States. Rising in northeastern Wyoming, in western Crook County about west of Devil's Tower, it flows northeastward, across a corner of southeastern Montana, and into South Dakota...

G560 mi
(901 km)
J9,550 mi2
(24,730 km2)
j533 cuft/s
(15.1 m3/s)
Osage River
Osage River
The Osage River is a tributary of the Missouri River in central Missouri in the United States. The Osage River is one of the larger rivers in Missouri. The river drains a mostly rural area of . The watershed includes an area of east-central Kansas and a large portion of west-central and central...

H493 mi
(793 km)
G14,800 mi2
(38,330 km2)
B11,980 cuft/s
(339 m3/s)
Niobrara River
Niobrara River
The Niobrara River is a tributary of the Missouri River, approximately long, running through the U.S. states of Wyoming and Nebraska. The river drains one of the most arid sections of the Great Plains, and has a low flow for a river of its length...

I430 mi
(692 km)
H13,900 mi2
36,000 km2)
E1,720 cuft/s
(48.7 m3/s)
Cheyenne River
Cheyenne River
The Cheyenne River is a tributary of the Missouri River in the U.S. states of Wyoming and South Dakota. It is approximately 295 mi long and drains an area of...

J347 mi
(558 km)
D24,300 mi2
(62,940 km2)
F874 cuft/s
(24.7 m3/s)


Flow



By discharge, the Missouri is the ninth largest river of the United States, after the Mississippi, St. Lawrence, Ohio
Ohio River
The Ohio River is the largest tributary, by volume, of the Mississippi River. At the confluence, the Ohio is even bigger than the Mississippi and, thus, is hydrologically the main stream of the whole river system, including the Allegheny River further upstream...

, Columbia
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...

, Niagara
Niagara River
The Niagara River flows north from Lake Erie to Lake Ontario. It forms part of the border between the Province of Ontario in Canada and New York State in the United States. There are differing theories as to the origin of the name of the river...

, Yukon
Yukon River
The Yukon River is a major watercourse of northwestern North America. The source of the river is located in British Columbia, Canada. The next portion lies in, and gives its name to Yukon Territory. The lower half of the river lies in the U.S. state of Alaska. The river is long and empties into...

, Detroit
Detroit River
The Detroit River is a strait in the Great Lakes system. The name comes from the French Rivière du Détroit, which translates literally as "River of the Strait". The Detroit River has served an important role in the history of Detroit and is one of the busiest waterways in the world. The river...

, and St. Clair
St. Clair River
The St. Clair River is a river in central North America which drains Lake Huron into Lake St Clair, forming part of the international boundary between the Canadian province of Ontario and the U.S. state of Michigan...

 (though the latter two are often considered part of a strait
Strait
A strait or straits is a narrow, typically navigable channel of water that connects two larger, navigable bodies of water. It most commonly refers to a channel of water that lies between two land masses, but it may also refer to a navigable channel through a body of water that is otherwise not...

 between Lake Huron
Lake Huron
Lake Huron is one of the five Great Lakes of North America. Hydrologically, it comprises the larger portion of Lake Michigan-Huron. It is bounded on the east by the Canadian province of Ontario and on the west by the state of Michigan in the United States...

 and Lake Erie
Lake Erie
Lake Erie is the fourth largest lake of the five Great Lakes in North America, and the tenth largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also has the shortest average water residence time. It is bounded on the north by the...

). Among rivers of North America as a whole, it is thirteenth largest, after the Mississippi, Mackenzie
Mackenzie River
The Mackenzie River is the largest river system in Canada. It flows through a vast, isolated region of forest and tundra entirely within the country's Northwest Territories, although its many tributaries reach into four other Canadian provinces and territories...

, St. Lawrence, Ohio, Columbia, Niagara, Yukon, Detroit, St. Clair, Fraser
Fraser River
The Fraser River is the longest river within British Columbia, Canada, rising at Fraser Pass near Mount Robson in the Rocky Mountains and flowing for , into the Strait of Georgia at the city of Vancouver. It is the tenth longest river in Canada...

, Slave
Slave River
The Slave River is a Canadian river that flows from Lake Athabasca in northeastern Alberta and empties into Great Slave Lake in the Northwest Territories....

, and Koksoak
Koksoak River
The Koksoak River is a river in northern Quebec, Canada, the largest river in the Nunavik region. The Inuit village and region's administrative center Kuujjuaq lies on the shores of the Koksoak, about south from its mouth.The name Koksoak is believed to originate from Moravian missionaries who...

.

As the Missouri drains a predominantly semi-arid region, its discharge is much less than rivers of comparable length such as the Mackenzie or Yukon. The average flow of 86340 cuft/s divided by the size of the drainage basin works out to an average discharge of about 0.16 cuft/s per square mile. Due to the large size and dryness of the basin, flows also fluctuate significantly from year to year. The highest annual mean was 181800 cuft/s in 1993, and the lowest was 41690 cuft/s in 2006. Extremes of the flow vary even further. The largest discharge ever recorded was over 710000 cuft/s on July 31, 1993 during a historic flood
Great Flood of 1993
The Great Mississippi and Missouri Rivers Flood of 1993 occurred in the American Midwest, along the Mississippi and Missouri rivers and their tributaries, from April to October 1993. The flood was among the most costly and devastating to ever occur in the United States, with $15 billion in damages...

. The lowest, a mere 602 cuft/s, was measured on December 23, 1963.


Missouri River monthly discharges at Hermann, MO

First row indicates discharge in cfs; second row in m3/s
52400 67900 96300 119000 125000 124000 101000 73600 75400 76500 76000 61000
1484 1923 2727 3370 3540 3511 2860 2084 2135 2166 2152 1727




Missouri River average discharges at selected cities
First row indicates discharge in cfs; second row in m3/s
10326 26500 28670 32190 54820 67160 86340
292 750 812 912 1552 1902 2445



References:

Geology


The Rocky Mountains of southwestern Montana at the headwaters of the Missouri River first rose in the Laramide Orogeny
Laramide orogeny
The Laramide orogeny was a period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the orogeny are in dispute, as is the cause. The Laramide...

, a mountain-building
Mountain formation
Mountain formation refers to the geological processes that underlie the formation of mountains. These processes are associated with large-scale movements of the earth's crust ....

 episode that occurred from around 70 to 45 million years ago (the end of the Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...

 through the early Cenozoic
Cenozoic
The Cenozoic era is the current and most recent of the three Phanerozoic geological eras and covers the period from 65.5 mya to the present. The era began in the wake of the Cretaceous–Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and...

). This orogeny
Orogeny
Orogeny refers to forces and events leading to a severe structural deformation of the Earth's crust due to the engagement of tectonic plates. Response to such engagement results in the formation of long tracts of highly deformed rock called orogens or orogenic belts...

 uplifted
Tectonic uplift
Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...

 Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 rocks along the western side of the Western Interior Seaway
Western Interior Seaway
The Western Interior Seaway, also called the Cretaceous Seaway, the Niobraran Sea, and the North American Inland Sea, was a huge inland sea that split the continent of North America into two halves, Laramidia and Appalachia, during most of the mid- and late-Cretaceous Period...

, a vast shallow sea that stretched from the Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...

 to the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

, and deposited the sediments that now underlie much of the drainage basin of the Missouri River.
This Laramide uplift caused the sea to retreat and laid the framework for a vast drainage system of rivers flowing from the Rocky and Appalachian Mountains
Appalachian Mountains
The Appalachian Mountains #Whether the stressed vowel is or ,#Whether the "ch" is pronounced as a fricative or an affricate , and#Whether the final vowel is the monophthong or the diphthong .), often called the Appalachians, are a system of mountains in eastern North America. The Appalachians...

, the predecessor of the modern-day Mississippi watershed. The Laramide Orogeny is essential to modern Missouri River hydrology
Hydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...

, as snow and ice melt from the Rockies provide the majority of the flow of the Missouri and its tributaries.

The Missouri and many of its tributaries cross the Great Plains
Great Plains
The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...

, flowing over or cutting into the Ogallala Group
Ogallala Aquifer
The Ogallala Aquifer, also known as the High Plains Aquifer, is a vast yet shallow underground water table aquifer located beneath the Great Plains in the United States...

 and older mid-Cenozoic
Cenozoic
The Cenozoic era is the current and most recent of the three Phanerozoic geological eras and covers the period from 65.5 mya to the present. The era began in the wake of the Cretaceous–Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and...

 sedimentary rocks. The lowest major Cenozoic unit, the White River Formation, was deposited between approximately 35 and 29 million years ago and consists of claystone
Claystone
Claystone is a geological term used to describe a clastic sedimentary rock that is composed primarily of clay-sized particles ....

, sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

, limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

, and conglomerate
Conglomerate (geology)
A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...

. Channel sandstones and finer-grained overbank deposits of the fluvial
Fluvial
Fluvial is used in geography and Earth science to refer to the processes associated with rivers and streams and the deposits and landforms created by them...

  Arikaree Group were deposited between 29 and 19 million years ago. The Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

-age Ogallala and the slightly younger Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...

-age Broadwater Formation deposited atop the Arikaree Group, and are formed from material eroded off of the Rocky Mountains during a time of increased generation of topographic relief; these formations stretch from the Rocky Mountains nearly to the Iowa border and give the Great Plains much of their gentle but persistent eastward tilt, and also constitute a major aquifer
Aquifer
An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...

.

Immediately prior to the Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...

 Ice Age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...

, the Missouri River was likely split into three segments: an upper portion that drained northwards into Hudson Bay
Hudson Bay
Hudson Bay , sometimes called Hudson's Bay, is a large body of saltwater in northeastern Canada. It drains a very large area, about , that includes parts of Ontario, Quebec, Saskatchewan, Alberta, most of Manitoba, southeastern Nunavut, as well as parts of North Dakota, South Dakota, Minnesota,...

,
and middle and lower sections that flowed eastward down the regional slope.
As the Earth plunged into the Ice Age, a pre-Illinoian (or possibly the Illinoian) glaciation
Glacial period
A glacial period is an interval of time within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate within an ice age...

 diverted the Missouri River southeastwards towards its present confluence with the Mississippi and caused it to integrate into a single river system that cuts across the regional slope. In western Montana, the Missouri River is surmised to have once flowed north then east around the Bear Paw Mountains
Bear Paw Mountains
The Bear Paw Mountains are an insular-montane island range in North-Central Montana, USA, located approximately 10 miles south of Havre, Montana...

. Sapphire
Sapphire
Sapphire is a gemstone variety of the mineral corundum, an aluminium oxide , when it is a color other than red or dark pink; in which case the gem would instead be called a ruby, considered to be a different gemstone. Trace amounts of other elements such as iron, titanium, or chromium can give...

s are found in some spots along the river in western Montana. Advances of the continental ice sheets diverted the river and its tributaries, causing them to pool up into large temporary lakes such as Glacial Lakes Great Falls
Glacial Lake Great Falls
Glacial Lake Great Falls was a prehistoric proglacial lake which existed in what is now central Montana in the United States between 15,000 BCE and 11,000 BCE. Centered on the modern city of Great Falls, Montana, Glacial Lake Great Falls extended as far north as Cut Bank, Montana, and as far south...

, Musselshell and others. As the lakes rose the water in them often spilled across adjacent local drainage divides, creating now-abandoned channels and coulee
Coulee
Coulee is applied rather loosely to different landforms, all of which refer to a kind of valley or drainage zone.The word coulee comes from the Canadian French coulée, from French word couler meaning "to flow"....

s including the Shonkin Sag
Shonkin Sag
The Shonkin Sag is a prehistoric fluvioglacial landform located along the northern edge of the Highwood Mountains in the state of Montana in the United States. The Sag is a river channel formed by the Missouri River and glacial meltwater pouring from Glacial Lake Great Falls...

, 100 miles (160.9 km) long. When the glaciers retreated, the Missouri flowed in a new course along the south side of the Bearpaws and the lower part of the Milk River tributary took over the original main channel.

Nicknamed the “Big Muddy”, the Missouri certainly lives up to this name, transporting
Sediment transport
Sediment transport is the movement of solid particles , typically due to a combination of the force of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained...

 20-25 million short tons (18-23 million t) of sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

 per year. Before the construction of dams and levees, this load was many times higher, averaging 320 million short tons (290 million t) per year. Much of this sediment is derived from the river’s floodplain
Floodplain
A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...

, also called the meander belt; every time the river changed course, it would erode tons of soil and rocks from its banks. However, channeling and diking the river has kept it from reaching its natural sediment sources along most of its course. The creation of giant reservoirs has also trapped millions of tons of sediment since the 1940s. Despite this, the river still transports more than half the total silt that empties into the Gulf of Mexico; the Mississippi River Delta
Mississippi River Delta
The Mississippi River Delta is the modern area of land built up by alluvium deposited by the Mississippi River as it slows down and enters the Gulf of Mexico...

, formed by sediment deposits at the mouth of the Mississippi, constitutes a majority of sediments carried by the Missouri.

First peoples



Archaeological evidence, especially in Missouri, suggests that early humans have inhabited the Missouri River basin for at least 10,000 years. Although the exact time range of human occupation is much debated among historians, research in the 1920s suggested that man first made his presence here about 12,000 years ago, at the end of the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

. During the end of the last glacial period, a great migration of humans began, traveling via the Bering land bridge from Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

 into and throughout the Americas. As they traveled slowly over centuries, the Missouri River formed one of the main migration paths. For those that stayed in the Mississippi River basin, most settled in the Ohio Valley and the lower Mississippi Valley, but many, including the Mound builders, stayed along the Missouri, becoming the ancestors of the later indigenous peoples of the Great Plains.
The Native Americans that lived along the Missouri had access to ample resources of food, water, and shelter. Many migratory animals inhabited the plains at the time, providing them meat, clothing, and other everyday items; there were also great riparian
Riparian zone
A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by...

 areas along the river's shorelines that provided them with natural herbs and staple foods. No written records from the tribes and peoples of the pre-European period exist because they did not use writing. According to the writings of explorers, some of the major tribes along the Missouri River included the Otoe
Otoe tribe
The Otoe or Oto are a Native American people. The Otoe language, Chiwere, is part of the Siouan family and closely related to that of the related Iowa and Missouri tribes.-History:...

, Missouria, Omaha
Omaha (tribe)
The Omaha are a federally recognized Native American nation which lives on the Omaha Reservation in northeastern Nebraska and western Iowa, United States...

, Ponca
Ponca
The Ponca are a Native American people of the Dhegihan branch of the Siouan-language group. There are two federally recognized Ponca tribes: the Ponca Tribe of Nebraska and the Ponca Tribe of Indians of Oklahoma...

, Brulé
Brulé
The Brulé are one of the seven branches or bands of the Teton Lakota Sioux American Indian nation. They are known as Sičháŋǧu Oyáte , or "Burnt Thighs Nation," and so, were called Brulé by the French...

, Lakota, Sioux
Sioux
The Sioux are Native American and First Nations people in North America. The term can refer to any ethnic group within the Great Sioux Nation or any of the nation's many language dialects...

, Arikara
Arikara
Arikara are a group of Native Americans in North Dakota...

, Hidatsa
Hidatsa
The Hidatsa are a Siouan people, a part of the Three Affiliated Tribes. The Hidatsa's autonym is Hiraacá. According to the tribal tradition, the word hiraacá derives from the word "willow"; however, the etymology is not transparent and the similarity to mirahací ‘willows’ inconclusive...

, Mandan, Assiniboine, Gros Ventres
Gros Ventres
The Gros Ventre people , also known as the A'ani, A'aninin, Haaninin, and Atsina, are a historically Algonquian-speaking Native American tribe located in north central Montana...

 and Blackfeet
Blackfeet
The Piegan Blackfeet are a tribe of Native Americans of the Algonquian language family based in Montana, having lived in this area since around 6,500 BC. Many members of the tribe live as part of the Blackfeet Nation in northwestern Montana, with population centered in Browning...

.

Natives used the Missouri, at least to a limited extent, as a path of trade and transport. In addition, the river and its tributaries formed tribal boundaries. Lifestyles of the indigenous mostly centered around a semi-nomad
Nomad
Nomadic people , commonly known as itinerants in modern-day contexts, are communities of people who move from one place to another, rather than settling permanently in one location. There are an estimated 30-40 million nomads in the world. Many cultures have traditionally been nomadic, but...

ic culture; many tribes would have different summer and winter camps. However, the center of Native American wealth and trade lay along the Missouri River in the Dakotas region on its great bend south. A large cluster of walled Mandan, Hidatsa and Arikara villages situated on bluffs and islands of the river was home to thousands, and later served as a market and trading post used by early French and British explorers, wanderers and fur traders. Following the introduction of the horse
Horse
The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...

 to Missouri River tribes possibly from feral European-introduced populations, the natives' way of life changed dramatically. The use of the horse allowed them to travel greater distances, and thus facilitated hunting, communications and trade.

Once, tens of millions of American bison
American Bison
The American bison , also commonly known as the American buffalo, is a North American species of bison that once roamed the grasslands of North America in massive herds...

 (commonly called buffalo), one of the keystone species
Keystone species
A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. Such species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and...

 of the Great Plains and the Ohio Valley, roamed the plains of the Missouri River basin. Most Native American groups in the basin relied heavily on the bison as a food source, and their hides and bones served to create other household items. In time, the species came to benefit from the indigenous peoples' periodic controlled burnings of the grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...

s surrounding the Missouri, in order to clear out old and dead growth. However, after the arrival of Europeans in North America, both the bison and the Native Americans saw a rapid decline in population. Hunting eliminated bison populations east of the Mississippi River by 1833 and reduced the numbers in the Missouri basin to a mere few hundred. Foreign diseases such as smallpox
Smallpox
Smallpox was an infectious disease unique to humans, caused by either of two virus variants, Variola major and Variola minor. The disease is also known by the Latin names Variola or Variola vera, which is a derivative of the Latin varius, meaning "spotted", or varus, meaning "pimple"...

 raged across the land, decimating Native American populations. Parts of the Missouri River ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

 then crumbled with the sheer losses.

Early explorers



Jolliet and Marquette


The first known Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

ans to see the river were the French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 explorers Louis Jolliet
Louis Jolliet
Louis Jolliet , also known as Louis Joliet, was a French Canadian explorer known for his discoveries in North America...

 and Jacques Marquette
Jacques Marquette
Father Jacques Marquette S.J. , sometimes known as Père Marquette, was a French Jesuit missionary who founded Michigan's first European settlement, Sault Ste. Marie, and later founded St. Ignace, Michigan...

 in 1673. Shortly after looking at Piasa
Piasa
The Piasa or Piasa Bird is a Native American dragon depicted in one of two murals painted by Native Americans on bluffs above the Mississippi River. Its original location was at the end of a chain of limestone bluffs in Madison County, Illinois at present-day Alton, Illinois...

 petroglyph
Petroglyph
Petroglyphs are pictogram and logogram images created by removing part of a rock surface by incising, picking, carving, and abrading. Outside North America, scholars often use terms such as "carving", "engraving", or other descriptions of the technique to refer to such images...

 paintings on the bluffs above the Mississippi River near the present-day location of Alton, Illinois
Alton, Illinois
Alton is a city on the Mississippi River in Madison County, Illinois, United States, about north of St. Louis, Missouri. The population was 27,865 at the 2010 census. It is a part of the Metro-East region of the Greater St. Louis metropolitan area in Southern Illinois...

, they heard the Missouri rushing into the Mississippi. "Pekistanoui" or "Pekitanoui" was the Native American name that the explorers recorded for the Missouri. At the time, the Missouri was in flood, which made it look significantly larger than the main stem of the Mississippi.

Marquette wrote that natives had told him that it was just a six-day canoe trip up the river, some 60 miles (96.6 km), where it would be possible to portage
Portage
Portage or portaging refers to the practice of carrying watercraft or cargo over land to avoid river obstacles, or between two bodies of water. A place where this carrying occurs is also called a portage; a person doing the carrying is called a porter.The English word portage is derived from the...

 over to another river that would take people to what is now the state of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

 (which was definitely not true). Jolliet and Marquette never explored the Missouri beyond its mouth, and did not linger in the area for long.

Bourgmont


The Missouri remained formally unexplored and uncharted until Étienne de Veniard, Sieur de Bourgmont
Étienne de Veniard, Sieur de Bourgmont
Étienne de Veniard, Sieur de Bourgmont was a French explorer who documented his travels on the Missouri and Platte rivers in North America and made the first European maps of these areas. He wrote two accounts of his travels, which included descriptions of the Native American tribes he encountered...

 wrote "Exact Description of Louisiana, of Its Harbors, Lands and Rivers, and Names of the Indian Tribes That Occupy It, and the Commerce and Advantages to Be Derived Therefrom for the Establishment of a Colony" in 1713 followed in 1714 by "The Route to Be Taken to Ascend the Missouri River." In the two documents Bourgmont was the first to use the name "Missouri" to refer to the river, and he was to name many tributaries based on the Native American tribes that lived along them. However, it is unclear how far up the Missouri Bourgmont traveled. He is the documented first European discoverer of the Platte River. In his writings he described the blonde-haired Mandans, so it is possible that he made it as far north as their villages in central North Dakota. The names and locations were used by cartographer Guillaume Delisle
Guillaume Delisle
Guillaume Delisle was a French cartographer who lived in Paris.His father, Claude Delisle studied law and then later settled in Paris as private teacher in geography and history, and afterwards filled the office of royal censor...

 to create the first reasonably accurate map of the river.

Bourgmont was living with the Missouria tribe at a village near present-day Brunswick, Missouri
Brunswick, Missouri
Brunswick is a rural city in Carroll County, Missouri, United States. The population was 925 at the 2000 census. The Missouri Farmers Association was founded here in 1914. Today the city is considered the Pecan Capital of Missouri...

 with his Missouria wife and son. He had been on the lam
On the Lam
"On the Lam" is a song by Kele Okereke, lead singer and rhythm guitarist of the band Bloc Party, released as the third single from his debut solo album The Boxer. The music video was released on October 8, 2010, with the digital EP being released on October 25....

 from French authorities since 1706, when he deserted his post as commandant of Fort Detroit
Fort Detroit
Fort Pontchartrain du Détroit or Fort Détroit was a fort established by the French officer Antoine de la Mothe Cadillac in 1701. The location of the former fort is now in the city of Detroit in the U.S...

 after he was criticized by Antoine Laumet de La Mothe, sieur de Cadillac
Antoine Laumet de La Mothe, sieur de Cadillac
Antoine Laumet de La Mothe, sieur de Cadillac was a French explorer and adventurer in New France, now an area of North America stretching from Eastern Canada in the north to Louisiana in the south. Rising from a modest beginning in Acadia in 1683 as an explorer, trapper, and a trader of alcohol...

 for his handling of an attack
Siege of Fort Detroit
The Siege of Fort Detroit was an ultimately unsuccessful attempt by North American Indians to capture Fort Detroit during Pontiac's Rebellion. The siege was led primarily by Pontiac, an Ottawa war leader.-Background:...

 by the Ottawa tribe
Ottawa (tribe)
The Odawa or Ottawa, said to mean "traders," are a Native American and First Nations people. They are one of the Anishinaabeg, related to but distinct from the Ojibwe nation. Their original homelands are located on Manitoulin Island, near the northern shores of Lake Huron, on the Bruce Peninsula in...

 in which a priest, a French sergeant and 30 Ottawa were killed. Bourgmont had further infuriated the French by illegally trapping, and for immoral behavior when he showed up at French outposts with his Native American wife. However, Jean-Baptiste Le Moyne, Sieur de Bienville
Jean-Baptiste Le Moyne, Sieur de Bienville
Jean-Baptiste Le Moyne de Bienvillepronounce] was a colonizer, born in Montreal, Quebec and an early, repeated governor of French Louisiana, appointed 4 separate times during 1701-1743. He was a younger brother of explorer Pierre Le Moyne d'Iberville...

, founder of Louisiana, said that rather than arresting Bourgmont they should decorate him with the Cross of St. Louis
Order of Saint Louis
The Royal and Military Order of Saint Louis was a military Order of Chivalry founded on 5 April 1693 by Louis XIV and named after Saint Louis . It was intended as a reward for exceptional officers, and is notable as the first decoration that could be granted to non-nobles...

 and name him "commandant of the Missouri" to represent France on the entire river. Bourgmont's reputation was further enhanced when the Pawnee, who had been befriended by Bourgmont, massacred the Spanish Villasur expedition
Villasur expedition
The Villasur expedition of 1720 was a Spanish military expedition intended to check the growing French presence on the Great Plains of central North America...

 in 1720 near modern day Columbus, Nebraska
Columbus, Nebraska
Columbus is a city in east central Nebraska, United States. Its population was 22,111 at the 2010 census. It is the county seat of Platte County.-Pre-settlement history:...

, which temporarily ended Spanish designs on the Missouri River and cleared the way for a New France
New France
New France was the area colonized by France in North America during a period beginning with the exploration of the Saint Lawrence River by Jacques Cartier in 1534 and ending with the cession of New France to Spain and Great Britain in 1763...

 empire stretching from Montreal, Canada to present-day New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

.
After squabbling with French authorities over financing of a new fort on the Missouri and also suffering an yearlong illness, Bourgmont established Fort Orleans
Fort Orleans
Fort Orleans was a French fort in colonial North America, the first fort built by any European forces on the Missouri River. It was built near the mouth of the Grand River near present-day Brunswick. Intended to be the linchpin in the vast New France empire stretching from Montreal to New Mexico,...

 in late 1723. It was the first fort and first longer term European settlement of any kind on the Missouri River, situated near present day Brunswick in the north-central part of what is now the state of Missouri. In 1724 Bourgmont led an expedition to enlist Comanche
Comanche
The Comanche are a Native American ethnic group whose historic range consisted of present-day eastern New Mexico, southern Colorado, northeastern Arizona, southern Kansas, all of Oklahoma, and most of northwest Texas. Historically, the Comanches were hunter-gatherers, with a typical Plains Indian...

 support in the fight against the Spanish. The following year, he brought the chiefs of several Missouri River tribes to Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

 to see the glory of France, including the palaces of Versailles
Palace of Versailles
The Palace of Versailles , or simply Versailles, is a royal château in Versailles in the Île-de-France region of France. In French it is the Château de Versailles....

 and Fontainebleau and a hunting expedition on a royal preserve with Louis XV. Bourgmont was raised to the rank of the nobility, remained in France and did not accompany the chiefs back to the New World. Fort Orleans was either abandoned or its small contingent was massacred by Native Americans in 1726.

Mackay and Evans


The Spanish took over the Missouri River in the 1763 Treaty of Paris
Treaty of Paris (1763)
The Treaty of Paris, often called the Peace of Paris, or the Treaty of 1763, was signed on 10 February 1763, by the kingdoms of Great Britain, France and Spain, with Portugal in agreement. It ended the French and Indian War/Seven Years' War...

 that ended the French and Indian War
French and Indian War
The French and Indian War is the common American name for the war between Great Britain and France in North America from 1754 to 1763. In 1756, the war erupted into the world-wide conflict known as the Seven Years' War and thus came to be regarded as the North American theater of that war...

, the North American theater of the Seven Years' War
Seven Years' War
The Seven Years' War was a global military war between 1756 and 1763, involving most of the great powers of the time and affecting Europe, North America, Central America, the West African coast, India, and the Philippines...

. The Spanish claim to the Missouri was based on Hernando de Soto's
Hernando de Soto (explorer)
Hernando de Soto was a Spanish explorer and conquistador who, while leading the first European expedition deep into the territory of the modern-day United States, was the first European documented to have crossed the Mississippi River....

 "discovery" of the Mississippi River on May 8, 1541. The Spanish initially did not extensively explore the river and let French fur traders continue their activities, although under license only. After the British began to exert influence on the upper Missouri River watershed through the Hudson's Bay Company
Hudson's Bay Company
The Hudson's Bay Company , abbreviated HBC, or "The Bay" is the oldest commercial corporation in North America and one of the oldest in the world. A fur trading business for much of its existence, today Hudson's Bay Company owns and operates retail stores throughout Canada...

, news of English incursions came following an expedition by Jacques D’Eglise in 1790. The Spanish chartered the "Company of Discoverers and Explorers of the Missouri" (popularly referred to as the "Missouri Company") and offered a reward for the first person to reach the Pacific via the Missouri. In 1794 and 1795 expeditions led by Jean Baptiste Truteau and Antoine Simon Lecuyer de la Jonchšre did not even make it as far north as the Mandan villages in central North Dakota.

The most significant expedition, however, was the MacKay and Evans Expedition of 1795–1797. James MacKay and John Evans
John Evans (explorer)
John Thomas Evans was a Welsh explorer who produced an early map of the Missouri River.John Evans was born in Waunfawr, near Caernarfon...

 were hired by the Spanish to find a route to the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 and to tell the British to leave the upper Missouri. MacKay and Evans established a winter camp about 20 miles (32.2 km) south of present-day Sioux City, Iowa
Sioux City, Iowa
Sioux City is a city in Plymouth and Woodbury counties in the western part of the U.S. state of Iowa. The population was 82,684 in the 2010 census, a decline from 85,013 in the 2000 census, which makes it currently the fourth largest city in the state....

, on the Nebraska side where they built Fort Charles. Evans went on to the Mandan villages, where he expelled the British traders. While talking to Native Americans they pinpointed the location of the Yellowstone River
Yellowstone River
The Yellowstone River is a tributary of the Missouri River, approximately long, in the western United States. Considered the principal tributary of the upper Missouri, the river and its tributaries drain a wide area stretching from the Rocky Mountains in the vicinity of the Yellowstone National...

, which they called "Yellow Rock" or "Roche Jaune" by the French traders. They created a detailed map of the upper Missouri that was used by Lewis and Clark
Lewis and Clark Expedition
The Lewis and Clark Expedition, or ″Corps of Discovery Expedition" was the first transcontinental expedition to the Pacific Coast by the United States. Commissioned by President Thomas Jefferson and led by two Virginia-born veterans of Indian wars in the Ohio Valley, Meriwether Lewis and William...

.

Lewis and Clark


On October 27, 1795, the United States and Spain signed Pinckney's Treaty
Pinckney's Treaty
Pinckney's Treaty, also known as the Treaty of San Lorenzo or the Treaty of Madrid, was signed in San Lorenzo de El Escorial on October 27, 1795 and established intentions of friendship between the United States and Spain. It also defined the boundaries of the United States with the Spanish...

, giving American merchants the "right of deposit" in New Orleans, meaning they could use the port to store goods for export. The treaty also recognized American rights to navigate the entire Mississippi River. In 1798, Spain revoked the treaty and on October 1, 1800, the Spanish secretly returned Louisiana to the French under Napoleon in the Third Treaty of San Ildefonso
Third Treaty of San Ildefonso
The Third Treaty of San Ildefonso was a secretly negotiated treaty between France and Spain in which Spain returned the colonial territory of...

. The transfer was so secret that the Spanish continued to administer the territory. In 1801, they restored the United States rights to use the river and New Orleans.


President Thomas Jefferson
Thomas Jefferson
Thomas Jefferson was the principal author of the United States Declaration of Independence and the Statute of Virginia for Religious Freedom , the third President of the United States and founder of the University of Virginia...

, fearing the cutoffs could occur again, sought to negotiate with France to buy New Orleans for $10 million. Napoleon countered with an offer of $15 million for all of the Louisiana Territory including the Missouri River. The deal was signed on May 2, 1803. On June 20, 1803, Thomas Jefferson instructed Meriwether Lewis
Meriwether Lewis
Meriwether Lewis was an American explorer, soldier, and public administrator, best known for his role as the leader of the Lewis and Clark Expedition also known as the Corps of Discovery, with William Clark...

 to explore the Missouri and look for a water route to the Pacific. Although the deal was signed, Spain still balked at an American takeover, citing that France had never formally taken over the Louisiana Territory. Spain was to formally tell Lewis not to take the journey and expressly forbade Lewis from seeing the McKay and Evans map which was the most detailed and accurate of its time. Lewis gained access to it surreptitiously. To avoid jurisdictional issues with Spain they wintered in 1803–1804 at Camp Dubois
Camp Dubois
Camp Dubois, near present day Hartford, Illinois, served as the winter camp for the Lewis and Clark Expedition from December 12, 1803, to May 14, 1804.It was located on the east side of the Mississippi River so that it was still in United States territory...

 on the Illinois (United States) side of the Mississippi.

Merriweather Lewis and William Clark began their expedition
Lewis and Clark Expedition
The Lewis and Clark Expedition, or ″Corps of Discovery Expedition" was the first transcontinental expedition to the Pacific Coast by the United States. Commissioned by President Thomas Jefferson and led by two Virginia-born veterans of Indian wars in the Ohio Valley, Meriwether Lewis and William...

 on May 18, 1804, traveling up the Missouri River with a party of thirty-three people in three boats. They spent the following winter on the river in North Dakota
North Dakota
North Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....

 and followed the Missouri all the way to its headwaters, upon where they crossed the Rocky Mountains and traveled to the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

. Their travels produced some of the first accurate maps of the northwestern United States and the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...

, providing a foundation for future explorers and emigrants. They also negotiated relations with multiple Native American tribes and wrote extensive reports on the climate, ecology and geology of the region. Many present-day geographic names in the region originated from their expedition.

Fur trade



As early as the 18th century, fur trappers entered the extreme northern basin of the Missouri River in the hopes of finding populations of beaver and otter, the sale of whose pelts drove the thriving North American fur trade
North American Fur Trade
The North American fur trade was the industry and activities related to the acquisition, exchange, and sale of animal furs in the North American continent. Indigenous peoples of different regions traded among themselves in the Pre-Columbian Era, but Europeans participated in the trade beginning...

. They came from many different places – some from the Canadian fur corporations at Hudson Bay
Hudson Bay
Hudson Bay , sometimes called Hudson's Bay, is a large body of saltwater in northeastern Canada. It drains a very large area, about , that includes parts of Ontario, Quebec, Saskatchewan, Alberta, most of Manitoba, southeastern Nunavut, as well as parts of North Dakota, South Dakota, Minnesota,...

, some from the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...

 (see also Maritime Fur Trade
Maritime Fur Trade
The Maritime Fur Trade was a ship-based fur trade system that focused on acquiring furs of sea otters and other animals from the indigenous peoples of the Pacific Northwest Coast and natives of Alaska. The furs were mostly sold in China in exchange for tea, silks, porcelain, and other Chinese...

), and some from the midwestern United States. Most did not stay in the area for long, as they failed to find significant resources.

The first glowing reports of country rich with thousands of game animals came in 1806 when Meriwether Lewis and William Clark returned from their two-year expedition. Their journals described lands rich with thousands of buffalo, beaver, and river otter; and also an abundant population of sea otter
Sea Otter
The sea otter is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean. Adult sea otters typically weigh between 14 and 45 kg , making them the heaviest members of the weasel family, but among the smallest marine mammals...

s on the Pacific Northwest coast. In 1807, explorer Manuel Lisa
Manuel Lisa
Manuel Lisa, also known as Manuel de Lisa , was a Spanish-American fur trader, explorer, and United States Indian agent. He was among the founders in St. Louis of the Missouri Fur Company, an early fur trading company...

 organized an expedition which would lead to the explosive growth of the fur trade in the upper Missouri River country. Lisa and his crew traveled up the Missouri and Yellowstone Rivers, trading manufactured items in return for furs from local Native American tribes, and established a fort at the confluence of the Yellowstone and a tributary, the Bighorn
Bighorn River
The Bighorn River is a tributary of the Yellowstone, approximately long, in the western United States in the states of Wyoming and Montana. The river was named in 1805 by fur trader François Larocque for the Bighorn Sheep he saw along its banks as he explored the Yellowstone River.The upper...

, in southern Montana. Although the business started small, its potential quickly grew it into a thriving trade.

Lisa's men started construction of Fort Raymond, which sat on a bluff overlooking the confluence of the Yellowstone and Bighorn, in the fall of 1807. The fort would serve primarily as a trading post for bartering with the Native Americans for furs. This method was unlike that of the Pacific Northwest fur trade, which involved trappers hired by the various fur enterprises, namely Hudson's Bay
Hudson's Bay Company
The Hudson's Bay Company , abbreviated HBC, or "The Bay" is the oldest commercial corporation in North America and one of the oldest in the world. A fur trading business for much of its existence, today Hudson's Bay Company owns and operates retail stores throughout Canada...

. Fort Raymond was later replaced by Fort Lisa
Fort Lisa (North Dakota)
The first Fort Lisa , also known as the Fort Manuel Lisa Trading Post and as Fort Manuel, was started by the notable fur trader Manuel Lisa of the Missouri Fur Company in 1809. It was located near the Gros Ventres village located between the mouth of the Little Missouri and that of the Big Knife...

 at the confluence of the Missouri and Yellowstone in North Dakota; a second fort also called Fort Lisa was built downstream on the Missouri River in Nebraska. In 1809 the St. Louis Missouri Fur Company was founded by Lisa in conjunction with William Clark and Pierre Choteau, among others.

Fur trapping activities in the early 19th century encompassed nearly all of the Rocky Mountains on both the eastern and western slopes. Trappers of the Hudson's Bay Company, St. Louis Missouri Fur Company, American Fur Company
American Fur Company
The American Fur Company was founded by John Jacob Astor in 1808. The company grew to monopolize the fur trade in the United States by 1830, and became one of the largest businesses in the country. The company was one the first great trusts in American business...

, Rocky Mountain Fur Company
Rocky Mountain Fur Company
The Rocky Mountain Fur Company, sometimes called Ashley's Hundred, was organized in St. Louis, Missouri in 1823 by General William H. Ashley and Major Andrew Henry . They posted advertisements in St. Louis newspapers seeking "One Hundred enterprising young men . ....

, North West Company
North West Company
The North West Company was a fur trading business headquartered in Montreal from 1779 to 1821. It competed with increasing success against the Hudson's Bay Company in what was to become Western Canada...

 and other outfits worked thousands of streams in the Missouri watershed as well as the neighboring Columbia, Colorado
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...

, Arkansas
Arkansas River
The Arkansas River is a major tributary of the Mississippi River. The Arkansas generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's initial basin starts in the Western United States in Colorado, specifically the Arkansas...

, Saskatchewan
Saskatchewan River
The Saskatchewan River is a major river in Canada, approximately long, flowing roughly eastward across Saskatchewan and Manitoba to empty into Lake Winnipeg...

 and other river basins. During this period, the trappers, also called mountain men, blazed trails through the wilderness that would later form the paths pioneers and settlers would travel by into the West. Transport of the thousands of beaver pelts required ships, providing one of the first large motives for river transport on the Missouri to start.

As the 1830s drew to a close, the fur industry slowly began to die as silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...

 replaced beaver fur as a desirable clothing item – by then, the beaver population of Rocky Mountains streams had been almost entirely decimated by intense hunting. Furthermore, frequent Native American attacks on trading posts made it dangerous for employees of the fur companies. In some regions, the industry continued well into the 1840s, but in others such as the Platte River valley, non-ideal conditions contributed to an earlier demise. The fur trade finally disappeared in the Great Plains around 1850, with the primary center of industry shifting to the Mississippi Valley and central Canada. Despite the demise of the once-thriving industry, however, its legacy led to the opening of the American West and a flood of settlers, farmers, ranchers, adventurers, hopefuls, financially bereft, and entrepreneurs took their place.

Settlers and pioneers


The river roughly defined the American frontier in the 19th century, particularly downstream from Kansas City, Missouri
Kansas City, Missouri
Kansas City, Missouri is the largest city in the U.S. state of Missouri and is the anchor city of the Kansas City Metropolitan Area, the second largest metropolitan area in Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties...

, where it takes a sharp eastern turn into the heart of the state of Missouri. All of the major trails for the opening of the American West have their starting points on the river, including the California
California Trail
The California Trail was an emigrant trail of about across the western half of the North American continent from Missouri River towns to what is now the state of California...

, Mormon
Mormon Trail
The Mormon Trail or Mormon Pioneer Trail is the 1,300 mile route that members of The Church of Jesus Christ of Latter-day Saints traveled from 1846 to 1868...

, Oregon
Oregon Trail
The Oregon Trail is a historic east-west wagon route that connected the Missouri River to valleys in Oregon and locations in between.After 1840 steam-powered riverboats and steamboats traversing up and down the Ohio, Mississippi and Missouri rivers sped settlement and development in the flat...

, and Santa Fe
Santa Fe Trail
The Santa Fe Trail was a 19th-century transportation route through central North America that connected Missouri with Santa Fe, New Mexico. Pioneered in 1822 by William Becknell, it served as a vital commercial and military highway until the introduction of the railroad to Santa Fe in 1880...

 trails. The first westward leg of the Pony Express
Pony Express
The Pony Express was a fast mail service crossing the Great Plains, the Rocky Mountains, and the High Sierra from St. Joseph, Missouri, to Sacramento, California, from April 3, 1860 to October 1861...

 was a ferry across the Missouri at St. Joseph, Missouri. Similarly, most emigrants arrived at the eastern terminus of the First Transcontinental Railroad
First Transcontinental Railroad
The First Transcontinental Railroad was a railroad line built in the United States of America between 1863 and 1869 by the Central Pacific Railroad of California and the Union Pacific Railroad that connected its statutory Eastern terminus at Council Bluffs, Iowa/Omaha, Nebraska The First...

 via a ferry ride across the Missouri between Council Bluffs, Iowa
Council Bluffs, Iowa
Council Bluffs, known until 1852 as Kanesville, Iowathe historic starting point of the Mormon Trail and eventual northernmost anchor town of the other emigrant trailsis a city in and the county seat of Pottawattamie County, Iowa, United States and is on the east bank of the Missouri River across...

 and Omaha, Nebraska
Omaha, Nebraska
Omaha is the largest city in the state of Nebraska, United States, and is the county seat of Douglas County. It is located in the Midwestern United States on the Missouri River, about 20 miles north of the mouth of the Platte River...

. True to the then-ideal of Manifest Destiny
Manifest Destiny
Manifest Destiny was the 19th century American belief that the United States was destined to expand across the continent. It was used by Democrat-Republicans in the 1840s to justify the war with Mexico; the concept was denounced by Whigs, and fell into disuse after the mid-19th century.Advocates of...

, over 500,000 people set out from the river town of Independence
Independence, Missouri
Independence is the fourth largest city in the U.S. state of Missouri, and is contained within the counties of Jackson and Clay. It is part of the Kansas City Metropolitan Area...

 to their various destinations in the American West from the 1830s to the 1860s. These people had many reasons to embark on this strenuous year-long journey – economic crisis, and later gold strikes including the California Gold Rush
California Gold Rush
The California Gold Rush began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The first to hear confirmed information of the gold rush were the people in Oregon, the Sandwich Islands , and Latin America, who were the first to start flocking to...

, for example.


For most, the route took them up the Missouri to Omaha, Nebraska, where they would set out along the Platte River
Great Platte River Road
The Great Platte River Road was the convergence point for the Trapper's Trail, the Oregon Trail, the Mormon Trail, the California Trail, the Pony Express route, and the military road from Fort Leavenworth to Fort Laramie across Nebraska. The Road, which extended from the Second Fort Kearny to Fort...

, which flows from the Rocky Mountains in Wyoming and Colorado eastwards through the Great Plains. An early expedition led by Robert Stuart
Robert Stuart (explorer)
Robert Stuart was the son of Charles Stuart, a partner of John Jacob Astor who as one of the North West Company men, or Nor'westers, enlisted by Astor to help him found his intended fur empire...

 from 1812 to 1813 proved the Platte impossible to navigate by the dugout canoes they used, let alone the large sidewheelers and sternwheelers that would later ply the Missouri in increasing numbers. One explorer remarked that the Platte was "too thick to drink, too thin to plow". Nevertheless, the Platte provided an abundant and reliable source of water for the pioneers as they headed west in covered wagons.

During the 1860s, gold strikes in Montana, Colorado, Wyoming and northern Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...

 attracted another wave of hopefuls to the region. Although some freight was hauled overland, most transport to and from the gold fields was done through the Missouri River and its tributary the Kansas River
Kansas River
The Kansas River is a river in northeastern Kansas in the United States. It is the southwestern-most part of the Missouri River drainage, which is in turn the northwestern-most portion of the extensive Mississippi River drainage. Its name come from the Kanza people who once inhabited the area...

, as well as the Snake River
Snake River
The Snake is a major river of the greater Pacific Northwest in the United States. At long, it is the largest tributary of the Columbia River, the largest North American river that empties into the Pacific Ocean...

 in western Wyoming and the Bear River
Bear River (Utah)
The Bear River is a river, approximately long, in southwestern Wyoming, southeastern Idaho, and northern Utah, in the United States. The largest tributary of the Great Salt Lake, it drains a mountainous area and farming valleys northeast of the lake and southeast of the Snake River Plain...

 in Utah, Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....

 and Wyoming. It is estimated that of the passengers and freight hauled from the Midwest to Montana, over 80 percent were transported by boat, a journey that took 150 days in the upstream direction. A route more directly west into Colorado lay along the Kansas River and the Republican River
Republican River
The Republican River is a river in the central Great Plains of North America, flowing through the U.S. states of Nebraska and Kansas.-Geography:...

 as well as pair of smaller Colorado streams, Big Sandy Creek
Big Sandy Creek (Colorado)
Big Sandy Creek is a tributary of the Arkansas River noted for being the location of the Sand Creek Massacre. Big Sandy Creek starts near Peyton in El Paso County, Colorado and flows through Elbert, Lincoln, Cheyenne and Kiowa counties before it joins with the Arkansas River in Prowers county...

 and the South Platte River
South Platte River
The South Platte River is one of the two principal tributaries of the Platte River and itself a major river of the American Midwest and the American Southwest/Mountain West, located in the U.S. states of Colorado and Nebraska...

, to near Denver. The gold rushes precipitated the decline of the Bozeman Trail
Bozeman Trail
The Bozeman Trail was an overland route connecting the gold rush territory of Montana to the Oregon Trail. Its most important period was from 1863-1868. The flow of pioneers and settlers through territory of American Indians provoked their resentment and caused attacks. The U.S. Army undertook...

 as a popular emigration route, as it passed through land held by often-hostile Native Americans. Safer paths were blazed to the Great Salt Lake
Great Salt Lake
The Great Salt Lake, located in the northern part of the U.S. state of Utah, is the largest salt water lake in the western hemisphere, the fourth-largest terminal lake in the world. In an average year the lake covers an area of around , but the lake's size fluctuates substantially due to its...

 near Corinne, Utah
Corinne, Utah
Corinne is a city in Box Elder County, Utah, United States. The population was 685 at the 2010 census.-Geography:Corinne is located at ....

 during the gold rush period, which led to the large-scale settlement of the Rocky Mountains region and eastern Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...

.

As settlers expanded their holdings into the Great Plains they naturally ran into conflicts with Native American tribes over land. This resulted in frequent raids, massacres and armed conflicts, leading to the federal government creating multiple treaties
Treaty
A treaty is an express agreement under international law entered into by actors in international law, namely sovereign states and international organizations. A treaty may also be known as an agreement, protocol, covenant, convention or exchange of letters, among other terms...

 with the Plains tribes, which generally involved establishing borders and reserving lands for the indigenous. As with the majority of other U.S.-Native American treaties, these promises were soon broken, leading to huge wars. Over 1,000 battles, big and small, were fought between the U.S. military and Native Americans before the tribes were forced out of their land onto reservations. Conflicts between natives and settlers over the opening of the Bozeman Trail
Bozeman Trail
The Bozeman Trail was an overland route connecting the gold rush territory of Montana to the Oregon Trail. Its most important period was from 1863-1868. The flow of pioneers and settlers through territory of American Indians provoked their resentment and caused attacks. The U.S. Army undertook...

 in the Dakotas, Wyoming and Montana led to Red Cloud's War
Red Cloud's War
Red Cloud's War was an armed conflict between the Lakota, Northern Cheyenne, and Arapaho and the United States in the Wyoming Territory and the Montana Territory from 1866 to 1868. The war was fought over control of the Powder River Country in north central present day Wyoming...

, in which the Lakota and Cheyenne
Cheyenne
Cheyenne are a Native American people of the Great Plains, who are of the Algonquian language family. The Cheyenne Nation is composed of two united tribes, the Só'taeo'o and the Tsétsêhéstâhese .The Cheyenne are thought to have branched off other tribes of Algonquian stock inhabiting lands...

 fought against the U.S. Army. The fighting resulted in a complete Native American victory. In 1868, the Treaty of Fort Laramie
Treaty of Fort Laramie (1868)
The Treaty of Fort Laramie was an agreement between the United States and the Oglala, Miniconjou, and Brulé bands of Lakota people, Yanktonai Dakota, and Arapaho Nation signed in 1868 at Fort Laramie in the Wyoming Territory, guaranteeing to the Lakota ownership of the Black Hills, and further...

 was signed, which "guaranteed" the use of the Black Hills
Black Hills
The Black Hills are a small, isolated mountain range rising from the Great Plains of North America in western South Dakota and extending into Wyoming, USA. Set off from the main body of the Rocky Mountains, the region is something of a geological anomaly—accurately described as an "island of...

, Powder River Country
Powder River Country
The Powder River Country refers to an area of the Great Plains in northeastern Wyoming in the United States. The area is loosely defined between the Bighorn Mountains and the Black Hills, in the upper drainage areas of the Powder, Tongue, and Little Bighorn rivers.During the late 1860s, the area...

 and other regions surrounding the northern Missouri River to Native Americans without white intervention. Another significant military engagement on the Missouri River during this period was the 1861 Battle of Boonville
Battle of Boonville
The First Battle of Boonville was a minor skirmish of the American Civil War, occurring on June 17, 1861, near Boonville in Cooper County, Missouri. Although casualties were extremely light, the battle's strategic impact was far greater than one might assume from its limited nature...

, which did not affect Native Americans but rather was a turning point in the American Civil War
American Civil War
The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

 that allowed the Union
Union (American Civil War)
During the American Civil War, the Union was a name used to refer to the federal government of the United States, which was supported by the twenty free states and five border slave states. It was opposed by 11 southern slave states that had declared a secession to join together to form the...

 to seize control of transport on the river, discouraging the state of Missouri from joining the Confederacy
Confederate States of America
The Confederate States of America was a government set up from 1861 to 1865 by 11 Southern slave states of the United States of America that had declared their secession from the U.S...

.

However, the peace and freedom of the Native Americans did not last for long. The Great Sioux War of 1876-77
Great Sioux War of 1876-77
The Great Sioux War of 1876, also known as the Black Hills War, was a series of battles and negotiations which occurred between 1876 and 1877 involving the Lakota and Northern Cheyenne, against the United States...

 was sparked when American miners discovered gold in the Black Hills of western South Dakota and eastern Wyoming. These lands were originally set aside for Native American use by the Treaty of Fort Laramie. When the settlers intruded onto the lands, they were attacked by Native Americans. U.S. troops were sent to the area to protect the miners, and drive out the natives from the new settlements. During this bloody period, both the Native Americans and the U.S. military won victories in major battles, resulting in the loss of nearly a thousand lives. The war eventually ended in a U.S. victory; Native Americans were relocated to reservations in Wyoming and Montana, and the Black Hills were given to the settlers.

The Hannibal Bridge
Hannibal Bridge
The First Hannibal Bridge was the first bridge to cross the Missouri River and was to establish Kansas City, Missouri as a major city and rail center....

 was the first bridge to cross the river when it opened in Kansas City in 1869 and traffic on the bridge was a major reason why Kansas City became the largest city on the river upstream from its mouth at St. Louis. Extensive use of paddle steamer
Paddle steamer
A paddle steamer is a steamship or riverboat, powered by a steam engine, using paddle wheels to propel it through the water. In antiquity, Paddle wheelers followed the development of poles, oars and sails, where the first uses were wheelers driven by animals or humans...

s on the upper river helped facilitate European settlement of the Dakotas
Dakota Territory
The Territory of Dakota was an organized incorporated territory of the United States that existed from March 2, 1861, until November 2, 1889, when the final extent of the reduced territory was split and admitted to the Union as the states of North and South Dakota.The Dakota Territory consisted of...

 and Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

. The Department of the Missouri
Department of the Missouri
Department of the Missouri was a division of the United States Army that functioned through the American Civil War and the Indian Wars afterwards.-Civil War:...

, which was headquartered on the banks of the river at Fort Leavenworth, Kansas, was the military command center for the Indian Wars
Indian Wars
American Indian Wars is the name used in the United States to describe a series of conflicts between American settlers or the federal government and the native peoples of North America before and after the American Revolutionary War. The wars resulted from the arrival of European colonizers who...

 in the region. The northernmost navigable point on the Missouri before extensive navigation improvements was Fort Benton
Fort Benton, Montana
Fort Benton is a city in and the county seat of Chouteau County, Montana, United States. A portion of the city was designated as a National Historic Landmark District in 1961. Established a full generation beforethe U.S...

, at approximately 2620 feet (798.6 m), which lay at the confluence of the Missouri and Marias
Marias River
The Marias River is a tributary of the Missouri River, approximately 210 mi long, in the U.S. state of Montana. It is formed in the Blackfeet Indian Reservation in Glacier County, in northwestern Montana, by the confluence of the Cut Bank Creek and the Two Medicine River...

 rivers and was the destination of many pioneers heading into western Montana.

Dams and engineering


In the 20th century a great number of dams were built along the Missouri River, transforming parts of its course into one of the largest reservoir
Reservoir
A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

 systems of North America. The Missouri's heavy sediment loads resulted in consistent course changes; its banks originally could shift a half-mile in an year, destroying property and infrastructure. Furthermore, the silt reduced the depth of its channel, exacerbating the power of floods and hindering navigation. As early as the 1860s, plans were already being considered for major alterations in the Missouri basin, and the first dams were built in the 1890s to generate electricity. The 1940s saw two grand proposals put forward for hydrologic modifications on the Missouri: the Pick-Sloan Plan, and the Missouri River Bank Stabilization and Navigation Project. The USACE took the job of implementing these plans, which called for the construction of levee
Levee
A levee, levée, dike , embankment, floodbank or stopbank is an elongated naturally occurring ridge or artificially constructed fill or wall, which regulates water levels...

s, the excavation of new channels, and the creation of six major dams that transformed 35 percent of the river's course into a chain of reservoirs. A total of fifteen dams, large and small, now impound long reaches of the Missouri River from south of Helena, Montana
Helena, Montana
Helena is the capital city of the U.S. state of Montana and the county seat of Lewis and Clark County. The 2010 census put the population at 28,180. The local daily newspaper is the Independent Record. The Helena Brewers minor league baseball and Helena Bighorns minor league hockey team call the...

 to Yankton, South Dakota
Yankton, South Dakota
Yankton is a city in, and the county seat of, Yankton County, South Dakota, United States. The population was 14,454 at the 2010 census. Yankton was the original capital of Dakota Territory. It is named for the Yankton tribe of Nakota Native Americans...

.


Violent floods struck the Missouri basin in 1844
Great Flood of 1844
The Great Flood of 1844 is the biggest flood ever recorded on the Missouri River and Upper Mississippi River, in North America, in terms of discharge.The impact was not as great as subsequent floods because of the small population in the region at the time...

, 1881
Great Flood of 1881
The Great Flood of 1881 refers to flooding events on the Missouri River during the spring of 1881. The flood struck Omaha, Nebraska and Council Bluffs, Iowa between April 1, 1881 and April 27, 1881...

, 1903, 1908, 1915, 1926–1927
Great Mississippi Flood of 1927
The Great Mississippi Flood of 1927 was the most destructive river flood in the history of the United States.-Events:The flood began when heavy rains pounded the central basin of the Mississippi in the summer of 1926. By September, the Mississippi's tributaries in Kansas and Iowa were swollen to...

 and 1934. In the 1930s, the central United States suffered a devastating drought that led to the Dust Bowl
Dust Bowl
The Dust Bowl, or the Dirty Thirties, was a period of severe dust storms causing major ecological and agricultural damage to American and Canadian prairie lands from 1930 to 1936...

 in Oklahoma
Oklahoma
Oklahoma is a state located in the South Central region of the United States of America. With an estimated 3,751,351 residents as of the 2010 census and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...

, Kansas
Kansas
Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...

 and the surrounding states. Then in 1943, severe flooding wreaked havoc in the watershed of the Missouri and set new records for flood levels in rivers across the central US. This flood caused $1.4 million (about $17.85 million in 2011 dollars) of damage in Omaha when the river breached a levee, destroying over 100 buildings and killing one person. It resulted in great economic loss because of the destruction of millions of acres of farmland, and hampered U.S. military efforts as World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 was then in progress and many war supplies were being manufactured in Omaha, Kansas City and other major cities along the Missouri. Floods and droughts have also caused problems for barge traffic along the Missouri; the river's shallowness, shifting channel and large amounts of underwater and floating debris tended to ground and sink boats.

"[The Missouri's temperament was] uncertain as the actions of a jury or the state of a woman's mind."
–Sioux City Register, March 28, 1868

From the first decade of the 20th century to the 1940s, a series of dams was built on the Missouri in the vicinity of Great Falls, Montana
Great Falls, Montana
Great Falls is a city in and the county seat of Cascade County, Montana, United States. The population was 58,505 at the 2010 census. It is the principal city of the Great Falls, Montana Metropolitan Statistical Area, which encompasses all of Cascade County...

, to generate power from the Great Falls of the Missouri, a series of five giant waterfalls formed by the river in its path through western Montana. Black Eagle Dam
Black Eagle Dam
Black Eagle Dam is a hydroelectric gravity weir dam located on the Missouri River in the city of Great Falls, Montana. The first dam on the site, built and opened in 1890, was a timber-and-rock crib dam. This structure was the first hydroelectric dam built in Montana and the first built on the...

, built in 1891 on Black Eagle Falls, was one of the earliest dams built on the Missouri and the first built in this area. The structure was little more than a weir
Weir
A weir is a small overflow dam used to alter the flow characteristics of a river or stream. In most cases weirs take the form of a barrier across the river that causes water to pool behind the structure , but allows water to flow over the top...

 a few feet high atop Black Eagle Falls, diverting part of the Missouri's flow into the Black Eagle power plant. The main and present structure of the Black Eagle Dam, built in 1926, supplemented power to the hydroelectric
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...

 plant, which was replaced in that year with a more modern unit. The largest, Ryan Dam
Ryan dam
Ryan Dam is a hydroelectric dam on the Missouri River, ten miles downstream from the city of Great Falls in the U.S. state of Montana. The dam is long and high; its reservoir is long and has a storage capacity of . It is a run-of-river dam. The dam is built on the largest of the five Great...

, was built in 1913, directly on top of the Grand Falls, the largest waterfall of the Missouri at 87 feet (26.5 m) high.

In that same time period, the Montana Power Company
Montana Power Company
The Montana Power Company was an electric utility company based in Butte, Montana which provided electricity to Montana consumers and industry from 1912 to 1997.- History :...

 and several other smaller enterprises began a series of hydroelectric projects on the upper Missouri River, above Great Falls and below Helena, Montana
Helena, Montana
Helena is the capital city of the U.S. state of Montana and the county seat of Lewis and Clark County. The 2010 census put the population at 28,180. The local daily newspaper is the Independent Record. The Helena Brewers minor league baseball and Helena Bighorns minor league hockey team call the...

. A small run-of-the river
Run-of-the-river hydroelectricity
Run-of-the-river hydroelectricity is a type of hydroelectric generation whereby a considerably smaller water storage called pondage or none is used to supply a power station. Run-of-the-river power plants are classified as with or without pondage...

 structure at the present site of Canyon Ferry Dam
Canyon Ferry Dam
Canyon Ferry Dam is a concrete gravity dam in a narrow valley of the Missouri River where the Big Belt Mountains and the Spokane Hills merge, approximately downstream from the confluence of the Gallatin, Madison, and Jefferson Rivers, and about east of the city of Helena, Montana...

 that was completed in 1898 became the second dam to be built on the Missouri; it generated seven and a half megawatts of electricity for Helena and the surrounding countryside. Another dam, the nearby steel
Steel dam
A steel dam is a type of dam that is made of steel, rather than the more common masonry, earthworks, concrete or timber construction materials.Relatively few examples were ever built...

 Hauser Dam
Hauser Dam
Hauser Dam is a hydroelectric straight gravity dam on the Missouri River about northeast of Helena, Montana, in the United States. The original dam, built between 1905 and 1907, failed in 1908 and caused severe flooding and damage downstream. A second dam was built on the site in 1908 and opened...

, was built from 1905 to 1907, but failed in 1908 because of structural deficiencies and heavy river flows, causing catastrophic flooding all the way downstream past Craig, Montana
Craig, Montana
Craig is an unincorporated community in Lewis and Clark County, Montana, United States. Craig is located along Interstate 15 north of Helena....

. At Great Falls, the Black Eagle Dam was dynamited in order to save a nearby smelter from inundation. Despite the disaster, the dam was rebuilt in 1910 by Montana Power Company using concrete, and stands to this day. Holter Dam
Holter Dam
Holter Dam is a hydroelectric straight gravity dam on the Missouri River about northeast of Helena, Montana, in the United States. The dam, which was built between 1908 and 1918, is long and high. The reservoir formed by the dam, Holter Lake is long and has a storage capacity of of water when...

 was the third dam built on this stretch of the Missouri River, about 45 miles (72.4 km) downstream of Helena. It was begun in 1909 by the Montana Power Company and the United Missouri River Power Company; construction finished in 1918. Its primary purpose was to generate about 48 megawatts of hydroelectricity. Construction of the present, much larger Canyon Ferry Dam by the U.S. Bureau of Reclamation (USBR) did not begin until 1949, and was completed in 1954.


Begun in 1944, the Pick-Sloan Plan called for a series of five reservoirs to be built along the main stem of the Missouri River and many more on its tributaries. Although originally separated into two distinct plans – the Sloan plan, which emphasized irrigation, and Pick plan, which called for flood control, navigation and hydroelectricity generation – the two were combined into one, which eventually totaled 90 major dams. All five were built; today the Missouri flows through Fort Peck
Fort Peck Dam
The Fort Peck Dam is the highest of six major dams along the Missouri River, located in northeast Montana in the United States, near Glasgow, and adjacent to the community of Fort Peck...

, Garrison
Garrison Dam
Garrison Dam is an earth-fill embankment dam on the Missouri River in central North Dakota. At over two miles in length, it is the fifth-largest earthen dam in the world, constructed by the U.S. Army Corps of Engineers from 1947-53...

, Oahe
Oahe Dam
The Oahe Dam is a large dam along the Missouri River, just north of Pierre, South Dakota in the United States. It creates Lake Oahe, the fourth largest artificial reservoir in the United States, which stretches up the course of the Missouri to Bismarck, North Dakota. The dam's powerplant provides...

, Big Bend
Big Bend Dam
Big Bend Dam is a major rolled earth dam along the Missouri River in central South Dakota.The dam, 95 feet high and 10,570 feet in length, was constructed as part of the Pick-Sloan Plan for Missouri watershed development authorized by the Flood Control Act of 1944. Construction began in 1959 and...

, Fort Randall
Fort Randall Dam
The Fort Randall Dam is an earth embankment dam impounding the Missouri River in South Dakota, United States and forming Lake Francis Case. It is one of six Missouri River dams, four being located in South Dakota....

 and Gavins Point
Gavins Point Dam
Gavins Point Dam is a hydroelectric dam on the Missouri River in the U.S. states of Nebraska and South Dakota. Built from 1952 to 1957, it impounds Lewis and Clark Lake. The dam is on the Nebraska-South Dakota border, west of Yankton, South Dakota....

 dams. The Fort Peck, Garrison and Oahe dams are among the largest dams in the world by volume; their sprawling reservoirs also rank within the biggest of the nation. The blueprints also included scores of dams on tributaries, such as the Yellowstone, the Bighorn
Bighorn River
The Bighorn River is a tributary of the Yellowstone, approximately long, in the western United States in the states of Wyoming and Montana. The river was named in 1805 by fur trader François Larocque for the Bighorn Sheep he saw along its banks as he explored the Yellowstone River.The upper...

, the Platte and the Kansas. While passing through government approval several major portions of the plan were canceled, including the construction of dams on the Yellowstone (this river is now the longest free-flowing river in the continental United States).

For a while, debate continued whether to build a low run-of-the-river dam at the Garrison Dam site, which would form Lake Sakakawea
Lake Sakakawea
Lake Sakakawea is a reservoir in the Missouri River basin in central North Dakota. Named for the Shoshone-Hidatsa woman Sakakawea, it is the third largest man-made lake in the United States, after Lake Mead and Lake Powell. The lake lies in parts of six counties in western North Dakota: Dunn,...

, or up to 27 on the Yellowstone and its tributaries. Eventually, it was decided to go with the former site, but with the construction of a much larger dam, because of its larger storage capacity and greater hydroelectric potential. This proposal was made by the USBR; however, the agency was not altogether heavily involved in the project. The Flood Control Act of 1944
Flood Control Act of 1944
The Pick-Sloan Flood Control Act of 1944 , enacted in the 2nd session of the 78th Congress, is U.S. legislation that authorized the construction of numerous dams and modifications to previously existing dams, as well as levees across the United States...

 (Pick-Sloan Legislation) was passed, clearing the way for the Pick-Sloan plan to begin. In the 1950s, construction commenced on the dams that would form the backbone of the plan. Eventually, the project was able to provide water to 4760000 acres (19,263.1 km²) of irrigated farmland and generated power from 17 hydroelectric plants.

A comprehensive list is given below of all fifteen dams on the Missouri River, ordered downstream. Many of the run-of-the-river dams on the Missouri form very small impoundments which may or may not have been given names; those unnamed will be left blank. Most of the dams are on the upper half of the river, otherwise they would impede navigation if built on the lower part of the Missouri.
Key
Pick-Sloan dam Run of the river dam



Dam Height State(s) Megawatts Reservoir Capacity
(KAF)
Toston
Toston Dam
Toston Dam is a hydroelectric gravity dam located on the Missouri River in Broadwater County, Montana. The dam is long and high, and generates 10 megawatts of power...

M56 ft (17.1 m) MT O10 3
Canyon Ferry
Canyon Ferry Dam
Canyon Ferry Dam is a concrete gravity dam in a narrow valley of the Missouri River where the Big Belt Mountains and the Spokane Hills merge, approximately downstream from the confluence of the Gallatin, Madison, and Jefferson Rivers, and about east of the city of Helena, Montana...

C225 ft (68.6 m) MT I50 Canyon Ferry Lake
Canyon Ferry Lake
thumb|Canyon Ferry LakeCanyon Ferry Lake is a reservoir on the Missouri River near Helena, Montana and Townsend, Montana. It is Montana's third largest body of water, covering 35,181 acres  and 76 miles  of shore . The dam was completed in 1954 and has been used for...

1,973
Hauser
Hauser Dam
Hauser Dam is a hydroelectric straight gravity dam on the Missouri River about northeast of Helena, Montana, in the United States. The original dam, built between 1905 and 1907, failed in 1908 and caused severe flooding and damage downstream. A second dam was built on the site in 1908 and opened...

H80 ft (24.4 m) MT M19 Hauser Lake 98
Holter
Holter Dam
Holter Dam is a hydroelectric straight gravity dam on the Missouri River about northeast of Helena, Montana, in the United States. The dam, which was built between 1908 and 1918, is long and high. The reservoir formed by the dam, Holter Lake is long and has a storage capacity of of water when...

F124 ft (37.8 m) MT J48 Holter Lake 243
Black Eagle
Black Eagle Dam
Black Eagle Dam is a hydroelectric gravity weir dam located on the Missouri River in the city of Great Falls, Montana. The first dam on the site, built and opened in 1890, was a timber-and-rock crib dam. This structure was the first hydroelectric dam built in Montana and the first built on the...

O13 ft (4 m) MT L21 Long Pool 2
Rainbow
Rainbow Dam
Rainbow Dam is a hydroelectric dam on the Missouri River, high and long, located six miles northeast of Great Falls in the U.S. state of Montana and just upstream of Rainbow Falls, a 45 ft waterfall that is the third of the five Great Falls of the Missouri. The dam, built in 1910, generates...

N29 ft (8.8 m) MT K36 1
Cochrane
Cochrane Dam
Cochrane Dam is a run-of-the river hydroelectric dam on the Missouri River, about northeast of Great Falls in the U.S. state of Montana. The dam has a concrete gravity design and is high and long. Its power station has two generators capable of producing 64 megawatts. Construction of the dam was...

K59 ft (18 m) MT G64 3
Ryan
Ryan dam
Ryan Dam is a hydroelectric dam on the Missouri River, ten miles downstream from the city of Great Falls in the U.S. state of Montana. The dam is long and high; its reservoir is long and has a storage capacity of . It is a run-of-river dam. The dam is built on the largest of the five Great...

J61 ft (18.6 m) MT H60 5
Morony
Morony Dam
Morony Dam is a hydroelectric gravity dam located on the Missouri River in Cascade County, Montana. The dam is long and high, and generates 48 megawatts of power.-About the dam:...

L59 ft (18 m) MT J48 3
Fort Peck
Fort Peck Dam
The Fort Peck Dam is the highest of six major dams along the Missouri River, located in northeast Montana in the United States, near Glasgow, and adjacent to the community of Fort Peck...

A250 ft (76.2 m) MT E185 Fort Peck Lake
Fort Peck Lake
Fort Peck Lake, or Lake Fort Peck, is a major reservoir in Montana, formed by the Fort Peck Dam on the Missouri River. The lake lies in the eastern prairie region of Montana approximately east of Great Falls and north of Billings, reaching into portions of six counties.The dam and reservoir were...

18,690
Garrison
Garrison Dam
Garrison Dam is an earth-fill embankment dam on the Missouri River in central North Dakota. At over two miles in length, it is the fifth-largest earthen dam in the world, constructed by the U.S. Army Corps of Engineers from 1947-53...

D210 ft (64 m) ND B515 Lake Sakakawea
Lake Sakakawea
Lake Sakakawea is a reservoir in the Missouri River basin in central North Dakota. Named for the Shoshone-Hidatsa woman Sakakawea, it is the third largest man-made lake in the United States, after Lake Mead and Lake Powell. The lake lies in parts of six counties in western North Dakota: Dunn,...

23,800
Oahe
Oahe Dam
The Oahe Dam is a large dam along the Missouri River, just north of Pierre, South Dakota in the United States. It creates Lake Oahe, the fourth largest artificial reservoir in the United States, which stretches up the course of the Missouri to Bismarck, North Dakota. The dam's powerplant provides...

B245 ft (74.7 m) SD A786 Lake Oahe
Lake Oahe
Lake Oahe is a large reservoir behind Oahe Dam on the Missouri River beginning in central South Dakota and continuing north into North Dakota in the United States. The lake has an area of and a maximum depth of . By volume, it is the fourth-largest reservoir in the US. Lake Oahe has a length of...

23,500
Big Bend
Big Bend Dam
Big Bend Dam is a major rolled earth dam along the Missouri River in central South Dakota.The dam, 95 feet high and 10,570 feet in length, was constructed as part of the Pick-Sloan Plan for Missouri watershed development authorized by the Flood Control Act of 1944. Construction began in 1959 and...

G95 ft (29 m) SD C493 Lake Sharpe
Lake Sharpe
Lake Sharpe is a large reservoir behind Big Bend Dam on the Missouri River in central South Dakota, USA. The lake has an area of and a maximum depth of . Lake Sharpe is approximately long, with a shoreline of ....

1,910
Fort Randall
Fort Randall Dam
The Fort Randall Dam is an earth embankment dam impounding the Missouri River in South Dakota, United States and forming Lake Francis Case. It is one of six Missouri River dams, four being located in South Dakota....

E165 ft (50.3 m) SD D320 Lake Francis Case
Lake Francis Case
Lake Francis Case is a large reservoir behind Fort Randall Dam on the Missouri River in south-central South Dakota, USA. The lake has an area of and a maximum depth of . Lake Francis Case has a length of approximately and has a shoreline of . The reservoir is named for former South Dakota Senator...

5,700
Gavins Point
Gavins Point Dam
Gavins Point Dam is a hydroelectric dam on the Missouri River in the U.S. states of Nebraska and South Dakota. Built from 1952 to 1957, it impounds Lewis and Clark Lake. The dam is on the Nebraska-South Dakota border, west of Yankton, South Dakota....

I74 ft (22.6 m) NE/SD F132 Lewis and Clark Lake
Lewis and Clark Lake
Lewis and Clark Lake is an impoundment on the Missouri River above Gavins Point Dam, near Yankton, South Dakota. It is located on the border of South Dakota and Nebraska. The reservoir is approximately long, with a surface area of 31,000 acres ; it has a maximum depth of . It is the smallest of...

492
Total 2,787 76,436

Navigation


"[Missouri River shipping] never achieved its expectations. Even under the very best of circumstances, it was never a huge industry."
~Richard Opper, former Missouri River Basin Association executive director

Boat travel on the Missouri first started with the wood-framed bull boat
Bull Boat
A Bull Boat is a small boat, usually made by American Indians and frontiersmen, made by covering a skeletal wooden frame with a buffalo hide.When traders of Hudson's Bay Company first visited the Mandan Indians in 1790 they found that tribe possessed of tublike boats with framework of willow poles,...

s and canoe
Canoe
A canoe or Canadian canoe is a small narrow boat, typically human-powered, though it may also be powered by sails or small electric or gas motors. Canoes are usually pointed at both bow and stern and are normally open on top, but can be decked over A canoe (North American English) or Canadian...

s of the Native Americans, which were used for thousands of years before the introduction of larger craft to the river upon colonization of the Great Plains. The first steamboat
Steamboat
A steamboat or steamship, sometimes called a steamer, is a ship in which the primary method of propulsion is steam power, typically driving propellers or paddlewheels...

 on the Missouri was the Independence, which started running between St. Louis and Keytesville
Keytesville, Missouri
Keytesville is a town in Chariton County, Missouri, United States. The population was 533 at the 2000 census. It is the county seat of Chariton County.-Geography:...

 around 1819. By the 1830s, large mail and freight-carrying vessels began operating on the river between Kansas City and St. Louis, and some even further up. A handful, such as the Western Engineer and the Yellowstone
Yellowstone (steamboat)
The steamboat Yellowstone was a side wheeler steamboat built in Louisville, Kentucky, for the American Fur Company for service on the Missouri River. By design, the Yellowstone was the first powered boat to reach above Council Bluff, Iowa, on the Missouri River achieving, on her maiden voyage,...

, were able to make it up the river as far as eastern Montana. At this time, the North American fur trade
North American Fur Trade
The North American fur trade was the industry and activities related to the acquisition, exchange, and sale of animal furs in the North American continent. Indigenous peoples of different regions traded among themselves in the Pre-Columbian Era, but Europeans participated in the trade beginning...

 was at its height, and more and more ships began traveling nearly the whole length of the Missouri from Montana's rugged Missouri Breaks to the mouth, carrying beaver and buffalo furs to and from the areas that the trappers frequented.
Water transport increased through the 1850s with multiple craft ferrying pioneers, emigrants and miners; many of these runs were from St. Louis or Independence to near Omaha. There, most of these people would set out overland along the broad, swift but shallow and unnavigable Platte River, which was described by pioneers as "a mile wide and an inch deep" and "the most magnificent and useless of rivers". By 1858, there were over 130 boats operating full-time on the Missouri, with many more smaller vessels. The industry's success, however, did not guarantee safety. In the early decades before the river's flow was controlled by man, its sketchy rises and falls and its massive amounts of sediment, which prevented a clear view of the bottom, wrecked some 300 boats. Because of the danger of navigating the Missouri River, the average ship's lifespan was short – about four years – before she was sunk or pulled out of service. Eventually, the completion of the First Transcontinental Railroad
First Transcontinental Railroad
The First Transcontinental Railroad was a railroad line built in the United States of America between 1863 and 1869 by the Central Pacific Railroad of California and the Union Pacific Railroad that connected its statutory Eastern terminus at Council Bluffs, Iowa/Omaha, Nebraska The First...

 ended steamboat commerce on the Missouri. The number of boats slowly dwindled, until there was almost nothing left by the mid-1880s.

Passage to Sioux City


Since the beginning of the 20th century, the Missouri River has been extensively engineered for water transport purposes. In 1912, the USACE was authorized to maintain the Missouri to a depth of six feet (1.8 m) from Kansas City, Missouri
Kansas City, Missouri
Kansas City, Missouri is the largest city in the U.S. state of Missouri and is the anchor city of the Kansas City Metropolitan Area, the second largest metropolitan area in Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties...

 to the mouth, a distance of 553 miles (890 km). This was accomplished by constructing levees and wing dam
Wing dam
A wing dam is a manmade barrier that, unlike a conventional dam, only extends partway into a river. These structures force water into a fast-moving center channel which reduces the rate of sediment accumulation, while slowing water flow near the riverbanks....

s to direct the river’s flow into a narrower, straighter channel and prevent sedimentation. In 1925, the USACE began a project to widen the navigation channel (the portion of the river's breadth maintained to a certain depth for the passage of large vessels) to 200 feet (61 m). Then, in 1927, the USACE started the dredging of a deep-water channel from Kansas City to Sioux City, Iowa
Sioux City, Iowa
Sioux City is a city in Plymouth and Woodbury counties in the western part of the U.S. state of Iowa. The population was 82,684 in the 2010 census, a decline from 85,013 in the 2000 census, which makes it currently the fourth largest city in the state....

. Channeling has reduced the river's length from 2540 miles (4,087.7 km) in the late 19th century to 2341 miles (3,767.5 km) in the present day.
All these revetment
Revetment
Revetments, or revêtements , have a variety of meanings in architecture, engineering and art history. In stream restoration, river engineering or coastal management, they are sloping structures placed on banks or cliffs in such a way as to absorb the energy of incoming water...

s, however, did not allow for the passage of large riverboats and barges. Construction of dams on the Missouri under the Pick-Sloan Plan in the 1950s aided navigation by regulating water flow. The six large reservoirs along the Missouri – Fort Peck, Sakakawea, Oahe, Francis Case, Sharpe, and Lewis and Clark – can hold a combined 74102000 acre.ft of water, more than one year's worth of the river's flow.

In 1945, the USACE began the Missouri River Bank Stabilization and Navigation Project, which would permanently increase the river’s navigation channel to a width of 300 feet (91.4 m) and a depth of nine feet (2.7 m). During work that continues to this day, the 735 miles (1,182.9 km) navigation channel from Sioux City to St. Louis has been controlled by building rock dikes to direct the river’s flow and scour out sediments, sealing and cutting off meanders and side channels, and dredging the riverbed. However, the naturally fast and shallow Missouri has at times resisted the efforts of the USACE to control its depth. In 2006, several U.S. Coast Guard work boats ran aground in the Missouri River because the navigation channel had been severely silted. The USACE was blamed for failing to maintain the channel to the minimum depth.
In 1929, the Missouri River Navigation Commission estimated the total amount of goods shipped on the river annually at 15 million tons (13.6 million metric tons), providing widespread consensus for the creation of a navigation channel. However, shipping traffic has since been far lower than expected – shipments of commodities including produce, manufactured items, lumber, and oil averaged only 8.2 million tons (7.4 million metric tons) per year from 1994 to 2006. Of the tonnage of materials shipped, Missouri is by far the largest user of the river accounting for 83 percent of river traffic – while Kansas has 12 percent, Nebraska three percent and Iowa two percent. Almost all of the barge traffic on the Missouri River ships sand and gravel dredged from the lower 500 miles (804.7 km) of the river; the remaining portion of the shipping channel now sees little to no use by commercial vessels.

Traffic decline


Tonnage of goods shipped by barges has seen a serious decline from the 1960s to the present on the Missouri River. In the 1960s, the USACE predicted an increase to 12 million annual tons (10.8 million metric tons) by 2000, but instead the opposite has happened. Tonnage of barge-shipped goods dropped from 3.3 million tons (3 million metric tons) in 1977 to just 1.3 million tons (1.18 million metric tons) in 2000. One of the largest drops has been in agricultural products, especially wheat
Wheat
Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...

. Part of the reason is that irrigated land along the Missouri has only been developed to a tenth of its potential. In 2006, barges on the Missouri hauled only 200,000 tons (181,437 metric tons) of products which is equal to the amount of daily freight traffic on the Mississippi.


Droughts and the development of other transportation systems have hampered river traffic on the Missouri in the late 20th and early 21st centuries. As shipping turns to other forms of transportation such as trucks and trains, annual boat traffic has dropped to 245,000 tons (222,260 metric tons) as of 2009, which is also "the first year of recovery after eight years of drought". Also, the failure of the USACE to consistently maintain the navigation channel has negatively impacted the industry. Currently, efforts are being made to revive the shipping industry on the Missouri River, because of the efficiency and cheapness of river transport to haul agricultural products, and the overcrowding of alternative transportation routes. Solutions such as expanding the navigation channel and releasing more water from reservoirs during the peak of the navigation season are being considered.

Ecology and human impact



Historically, the Missouri's floodplain
Floodplain
A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...

, an area thousands of square miles in size, supported a wide diversity of plant and animal species, generally increasing in size and variety as one proceeded downstream from the cold, relatively arid headwaters in Montana to the temperate, moist climate of Missouri. The river's riparian zone
Riparian zone
A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by...

 consisted primarily of cottonwoods, willow
Willow
Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...

s and sycamore
Platanus
Platanus is a small genus of trees native to the Northern Hemisphere. They are the sole living members of the family Platanaceae....

s, with several other types of trees such as maple
Maple
Acer is a genus of trees or shrubs commonly known as maple.Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in...

 and ash. The height of the trees generally increase farther from the riverbanks for a limited distance, as the roots of the trees closer to the river are vulnerable to soil erosion during floods. Because of its large sediment concentrations, the Missouri does not support many aquatic invertebrates. However, the basin does support 300 species of birds and 150 species of fish. The Missouri also supports several species of mammals in its aquatic and riparian habitats, such as mink
Mink
There are two living species referred to as "mink": the European Mink and the American Mink. The extinct Sea Mink is related to the American Mink, but was much larger. All three species are dark-colored, semi-aquatic, carnivorous mammals of the family Mustelidae, which also includes the weasels and...

s, river otters, beavers, muskrat
Muskrat
The muskrat , the only species in genus Ondatra, is a medium-sized semi-aquatic rodent native to North America, and introduced in parts of Europe, Asia, and South America. The muskrat is found in wetlands and is a very successful animal over a wide range of climates and habitats...

s, and raccoon
Raccoon
Procyon is a genus of nocturnal mammals, comprising three species commonly known as raccoons, in the family Procyonidae. The most familiar species, the common raccoon , is often known simply as "the" raccoon, as the two other raccoon species in the genus are native only to the tropics and are...

s.

The Missouri River basin is divided into three freshwater ecoregion
Ecoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...

s by the World Wide Fund For Nature
World Wide Fund for Nature
The World Wide Fund for Nature is an international non-governmental organization working on issues regarding the conservation, research and restoration of the environment, formerly named the World Wildlife Fund, which remains its official name in Canada and the United States...

: the Upper Missouri, Lower Missouri and Central Prairie. The Upper Missouri, encompassing an area roughly within Montana, Wyoming, southern Alberta and Saskatchewan, and North Dakota is defined by a continental climate
Continental climate
Continental climate is a climate characterized by important annual variation in temperature due to the lack of significant bodies of water nearby...

 with dry grasslands and sparse biodiversity because of Ice Age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...

 glaciations; there are no known endemic species. Except for the headwaters in the Rockies, there is little precipitation in this part of the watershed. The Middle Missouri ecoregion, extending through Colorado, southwestern Minnesota, northern Kansas, Nebraska, and parts of Wyoming and Iowa, has a temperate climate with moderate amounts of rainfall. Plant life is more diverse in the Middle Missouri but it does not have many species of fish. Finally, the Central Prairie ecoregion is situated on the lower part of the Missouri, encompassing all or parts of Missouri, Kansas, Oklahoma and Arkansas. This region has the greatest diversity of plants and animals of the three ecoregions, despite its large seasonal temperature fluctuations. There are 13 species of crayfish
Crayfish
Crayfish, crawfish, or crawdads – members of the superfamilies Astacoidea and Parastacoidea – are freshwater crustaceans resembling small lobsters, to which they are related...

 endemic to the lower Missouri.


Throughout its history of industrialization and commerce, the Missouri has been severely polluted and degraded by human activities along its shores; in addition, most of the river's floodplain habitat is long gone, replaced by irrigated agricultural land. Additionally, development of the floodplain has led to more and more people and industries within areas at high risk of inundation. Levees have been constructed along much of the river in order to keep floodwaters within the channel, but this also leads to faster stream velocity and thence increasing peak flows in downstream areas. A major problem in the river is the excess of fertilizer
Fertilizer
Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...

 runoff and resultantly, elevated levels of nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

. A large amount of fertilizer travels down the Missouri from farmland in the states of Iowa and Missouri, but it is not the most affected river in the Mississippi basin – the upper Mississippi, Illinois
Illinois River
The Illinois River is a principal tributary of the Mississippi River, approximately long, in the State of Illinois. The river drains a large section of central Illinois, with a drainage basin of . This river was important among Native Americans and early French traders as the principal water route...

 and Ohio Rivers are even more severely affected. The result of this pollution are algae blooms which result in oxygen depletion, and the vast Gulf of Mexico dead zone at the end of the Mississippi Delta.

Environmentalists contend that channelization of the lower Missouri waters, which made the river narrower, deeper, and less accessible to riparian flora and fauna, has caused massive biological loss. The construction of numerous dams and river bank control projects has converted over 300000 acres (1,214.1 km²) of Missouri River floodplain to agricultural land, and significantly reduced the volume of sediment transported downstream by the river and eliminating critical habitat for fish and amphibians, and nesting sites for birds. Declines in populations of these species prompted the U.S. Fish and Wildlife Service to issue a biological opinion in 2000 (amended in 2003) recommending restoration of river habitats for federally endangered bird and fish species.

In response, the U.S. Army Corps of Engineers began constructing restoration projects along the lower Missouri River in the early 2000s. Because of extremely low use of the shipping channel in the lower Missouri maintained by the U.S. Army Corps of Engineers, it is considered feasible to remove some of the levee, dikes, and wing dams that constrict the river’s flow, to allow it to naturally restore its environment. As of 2001, there were 87000 acres (352.1 km²) of riverside floodplain undergoing active restoration.

However, these restoration projects re-mobilized some of the sediments that had been trapped behind bank stabilization structures, prompting concerns that nutrients carried with the re-introduced sediments could exacerbate nutrient and sediment pollution locally and downstream in the northern Gulf of Mexico. A 2010 National Research Council
United States National Research Council
The National Research Council of the USA is the working arm of the United States National Academies, carrying out most of the studies done in their names.The National Academies include:* National Academy of Sciences...

 report assessed the roles of sediment in the Missouri River, evaluating current habitat restoration strategies and alternative ways to manage sediment. The report found that a better understanding of sediment processes in the Missouri River, including the creation of a “sediment budget”—an accounting of sediment transport, erosion, and deposition volumes for the length of the Missouri River— would provide a foundation for projects to improve water quality standards and protect endangered species.

Tourism and recreation



The Lewis and Clark National Historic Trail
Lewis and Clark National Historic Trail
The Lewis and Clark National Historic Trail is a route across the United States commemorating the Lewis and Clark Expedition of 1804 to 1806. It is part of the National Trails System of the United States...

, some 3700 miles (5,954.6 km) long, follows nearly the entire Missouri River from its mouth to its source, retracing the route of the Lewis and Clark Expedition. Extending from Wood River, Illinois
Wood River, Illinois
Wood River is a city in Madison County, Illinois, United States. The population was 11,296 at the 2000 census.-Geography:Wood River is located at ....

 in the east to Astoria, Oregon
Astoria, Oregon
Astoria is the county seat of Clatsop County, Oregon, United States. Situated near the mouth of the Columbia River, the city was named after the American investor John Jacob Astor. His American Fur Company founded Fort Astoria at the site in 1811...

 in the west, it also follows portions of the Mississippi River and Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...

. The trail, which spans through eleven U.S. states, is maintained by various federal and state government agencies; it passes through some 100 historic sites, notably archaeological locations including the Knife River Indian Villages National Historic Site
Knife River Indian Villages National Historic Site
The Knife River Indian Villages National Historic Site, which was established in 1974, preserves the historic and archaeological remnants of the Northern Plains Indians. This area was a major trading and agricultural area. There were three villages that occupied the Knife area. In general, these...

.

Parts of the river itself are also designated for recreational or preservational use. The Missouri National Recreational River
Missouri National Recreational River
The Missouri National Recreational River is located on the border between Nebraska and South Dakota. The designation was first applied in 1978 to a 59-mile section of the Missouri River between Gavins Point Dam and Ponca State Park. In 1991, an additional 39-mile section between Fort Randall Dam...

 consists of portions of the Missouri downstream from Gavins Point Dam
Gavins Point Dam
Gavins Point Dam is a hydroelectric dam on the Missouri River in the U.S. states of Nebraska and South Dakota. Built from 1952 to 1957, it impounds Lewis and Clark Lake. The dam is on the Nebraska-South Dakota border, west of Yankton, South Dakota....

 and Fort Randall Dam
Fort Randall Dam
The Fort Randall Dam is an earth embankment dam impounding the Missouri River in South Dakota, United States and forming Lake Francis Case. It is one of six Missouri River dams, four being located in South Dakota....

 that total 98 miles (157.7 km). These reaches of the river exhibit islands, meanders, sandbars, underwater rocks, riffles
Riffle-Pool Sequence
In a flowing stream, a riffle-pool sequence develops as a stream's hydrological flow structure alternates from areas of relatively shallow to deeper water. This sequence is present only in streams carrying gravel or coarser sediments. Riffles are formed in shallow areas by coarser materials such...

, snags, and other once-common features of the lower river that have now disappeared under reservoirs or have been destroyed by channeling.

Downstream from Great Falls, Montana, about 149 miles (239.8 km) of the river course through a rugged series of canyon
Canyon
A canyon or gorge is a deep ravine between cliffs often carved from the landscape by a river. Rivers have a natural tendency to reach a baseline elevation, which is the same elevation as the body of water it will eventually drain into. This forms a canyon. Most canyons were formed by a process of...

s and badlands
Badlands
A badlands is a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded by wind and water. It can resemble malpaís, a terrain of volcanic rock. Canyons, ravines, gullies, hoodoos and other such geological forms are common in badlands. They are often...

 known as the Missouri Breaks. This part of the river, designated a U.S. National Wild and Scenic River
National Wild and Scenic River
National Wild and Scenic River is a designation for certain protected areas in the United States.The National Wild and Scenic Rivers Act was an outgrowth of the recommendations of a Presidential commission, the Outdoor Recreation Resources Review Commission...

 in 1976, flows within the Upper Missouri Breaks National Monument, a 375000 acres (1,517.6 km²) preserve comprising steep cliffs, deep gorges, arid plains, badlands, archaeological sites, and whitewater rapids on the Missouri itself. The preserve also includes a wide variety of plant and animal life; recreational activities include boating, rafting, hiking and wildlife observation.

In north-central Montana, approximately 1100000 acres (4,451.5 km²) along over 125 miles (201.2 km) of the Missouri River, centering around Fort Peck Lake
Fort Peck Lake
Fort Peck Lake, or Lake Fort Peck, is a major reservoir in Montana, formed by the Fort Peck Dam on the Missouri River. The lake lies in the eastern prairie region of Montana approximately east of Great Falls and north of Billings, reaching into portions of six counties.The dam and reservoir were...

, comprise the Charles M. Russell National Wildlife Refuge
Charles M. Russell National Wildlife Refuge
Charles M. Russell National Wildlife Refuge surrounds Fort Peck Reservoir and at 1,100,000 acres is the largest refuge in Montana, United States. Created in 1936, the refuge was named after famed painter of the American West, Charles M. Russell...

. The wildlife refuge consists of a native northern Great Plains ecosystem that has not been heavily affected by human development, except for the construction of Fort Peck Dam. Although there are few designated trails, all the land within the preserve is open to hiking and camping.

Many U.S. national parks, such as Glacier National Park, Rocky Mountain National Park
Rocky Mountain National Park
Rocky Mountain National Park is a national park located in the north-central region of the U.S. state of Colorado.It features majestic mountain views, a variety of wildlife, varied climates and environments—from wooded forests to mountain tundra—and easy access to back-country trails...

, Yellowstone National Park
Yellowstone National Park
Yellowstone National Park, established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872, is a national park located primarily in the U.S. state of Wyoming, although it also extends into Montana and Idaho...

 and Badlands National Park
Badlands National Park
Badlands National Park, in southwest South Dakota, United States preserves of sharply eroded buttes, pinnacles, and spires blended with the largest protected mixed grass prairie in the United States....

 are in the watershed. Parts of other rivers in the basin are also set aside for preservation and recreational use – notably the Niobrara National Scenic River
Niobrara National Scenic River
The Niobrara National Scenic River is located in north-central Nebraska, United States, approximately 300 miles northwest of Omaha. In 1991, Congress set aside 76 miles along two stretches of the Niobrara River for preservation under the management of the National Park Service with assistance...

, which is a 76 miles (122.3 km) protected stretch of the Niobrara River
Niobrara River
The Niobrara River is a tributary of the Missouri River, approximately long, running through the U.S. states of Wyoming and Nebraska. The river drains one of the most arid sections of the Great Plains, and has a low flow for a river of its length...

, one of the Missouri's longest tributaries. National Historic Landmark
National Historic Landmark
A National Historic Landmark is a building, site, structure, object, or district, that is officially recognized by the United States government for its historical significance...

s on the river include Three Forks of the Missouri
Missouri Headwaters State Park
Missouri Headwaters State Park is a Montana state park that marks the official start of the Missouri River. It includes the Three Forks of the Missouri National Historic Landmark.It is located near Three Forks, Montana at an elevation of ....

, Fort Benton, Montana
Fort Benton, Montana
Fort Benton is a city in and the county seat of Chouteau County, Montana, United States. A portion of the city was designated as a National Historic Landmark District in 1961. Established a full generation beforethe U.S...

, Big Hidatsa Village Site
Big Hidatsa Village Site
Big Hidatsa Village Site is a Mercer County, North Dakota site significant for its well-defined depressions left from Hidatsa and Mandan earth lodges. It is the largest of three villages preserved in Knife River Indian Villages National Historic Site....

, Fort Atkinson, Nebraska
Fort Atkinson (Nebraska)
Fort Atkinson was the first United States Army post to be established west of the Missouri River in the unorganized region of the Louisiana Purchase of the United States. Located just east of present-day Fort Calhoun, Nebraska, the fort was erected in 1819 and abandoned in 1827...

 and Arrow Rock Historic District
Arrow Rock Historic District
Arrow Rock Historic District, or Arrow Rock, is a historic district in Arrow Rock, Missouri that was designated a National Historic Landmark...

.

See also



  • Across the Wide Missouri
    Across the Wide Missouri
    Across the Wide Missouri is a 1947 historical work by Bernard DeVoto. It is the second volume of a trilogy that includes The Year of Decision and The Course of Empire ....

  • Great bison belt
    Great bison belt
    The Great Bison Belt is a tract of rich grassland that ran from Alaska to the Gulf of Mexico around 9000 BC. The Great Bison Belt was supported by spring and early summer rainfall that allowed short grasses to grow...

  • List of longest main-stem rivers in the United States
  • List of crossings of the Missouri River
  • List of settlements along the Missouri River
  • Montana Stream Access Law
    Montana Stream Access Law
    The Montana Stream Access Law says that anglers, floaters and other recreationists in Montana have full use of most natural waterways between the high water marks for fishing and floating, along with swimming and other river or stream-related activities...

  • Montana Wilderness Association
    Montana Wilderness Association
    The Montana Wilderness Association was founded in 1958 by Montana volunteers and is governed by a state council of citizen volunteers from across the state, elected by the membership. As a community-based organization, it works at the local level through seven chapters and field offices in ...

  • Sacagawea
    Sacagawea
    Sacagawea ; was a Lemhi Shoshone woman, who accompanied the Lewis and Clark Expedition, acting as an interpreter and guide, in their exploration of the Western United States...



External links