The
Mackenzie River is the largest
riverA river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
system in
CanadaCanada 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...
. It flows through a vast, isolated region of forest and
tundraIn physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
entirely within the country's
Northwest TerritoriesThe Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...
, although its many tributaries reach into four other Canadian provinces and territories. The river's
mainstemMainstem may refer to:* Mainstem is the principal watercourse in a riverine drainage system with multiple named streams.* Mainstem bronchus is a medical term for a part of the respiratory system....
runs 1738 kilometres (1,079.9 mi) in a northerly direction to the
Arctic OceanThe 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...
, draining a vast area nearly the size of
IndonesiaIndonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. It is the largest river flowing into the Arctic from
North AmericaNorth 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 with its tributaries is one of the longest rivers in the world.
Course
Rising out of the marshy western end of
Great Slave LakeGreat Slave Lake is the second-largest lake in the Northwest Territories of Canada , the deepest lake in North America at , and the ninth-largest lake in the world. It is long and wide. It covers an area of in the southern part of the territory. Its given volume ranges from to and up to ...
, the Mackenzie River flows generally west-northwest for about 300 km (186.4 mi), passing the hamlets of
Fort ProvidenceFort Providence is a hamlet in the South Slave Region of the Northwest Territories, Canada...
and Brownings Landing. At
Fort SimpsonFort Simpson is a village in the Dehcho Region of the Northwest Territories, Canada. The community is located on an island at the confluence of the Mackenzie and Liard Rivers...
it is joined by the
Liard RiverThe Liard River flows through Yukon, British Columbia and the Northwest Territories, Canada. Rising in the Saint Cyr Range of the Pelly Mountains in southeastern Yukon, it flows southeast through British Columbia, marking the northern end of the Rocky Mountains and then curving northeast back...
, its largest tributary, then swings towards the Arctic, paralleling the Franklin Mountains as it receives the
North Nahanni RiverNorth Nahanni River is a river in the Northwest Territories of Canada. It is a major tributary of the Mackenzie River-Course:The North Nahanni River originates in the Backbone Ranges of the Mackenzie Mountains, at an elevation of . It flows east, south of the Thundercloud Range, then turns...
. The
Keele RiverThe Keele River is a tributary of the Mackenzie River, about long, in the western part of the Canadian Northwest Territories. Flowing in a generally northeast direction, it drains a sparsely populated, rugged area of the Mackenzie Mountains.-Course:...
enters from the left about 100 km (62.1 mi) above
TulitaTulita, which in Dene language means "where the rivers or waters meet," is a hamlet in the Sahtu Region of the Northwest Territories, Canada. It was formerly known as Fort Norman, until 1 January 1996...
, where the
Great Bear RiverThe -long Great Bear River, which drains the Great Bear Lake westward through marshes into the Mackenzie River, forms an important transportation link during its four ice-free months. It originates at south-west bay of the lake. The river has irregular meander pattern wide channel with average depth...
joins the Mackenzie. Just before crossing the
Arctic CircleThe Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....
, the river passes Norman Wells, then continues northwest to merge with the
Arctic RedThe Arctic Red River is the name of a tributary to the Mackenzie River in the Northwest Territories, Canada.In 1993 the river was designated as part of the Canadian Heritage Rivers System. It was also the name of a community on the Mackenzie where the river joins, now known as Tsiigehtchic...
and
PeelThe Peel River may refer to:*Peel River in Australia*Peel River in the Yukon and Northwest Territories, Canada...
rivers. It finally empties into the
Beaufort SeaThe Beaufort Sea is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, west of Canada's Arctic islands. The sea is named after hydrographer Sir Francis Beaufort...
, part of the Arctic Ocean, through the vast
Mackenzie DeltaMackenzie Delta may refer to:* Mackenzie River, that originates in Great Slave Lake, in the Northwest Territories, and flows north into the Arctic Ocean...
.
Most of the Mackenzie River is a broad, slow-moving waterway; its elevation drops just 156 metres (511.8 ft) from source to mouth. It is a
braided riverA braided river is one of a number of channel types and has a channel that consists of a network of small channels separated by small and often temporary islands called braid bars or, in British usage, aits or eyots. Braided streams occur in rivers with high slope and/or large sediment load...
for much of its length, characterized by numerous sandbars and side channels. The river ranges from 2 to 5 km (1.2 to 3.1 mi) wide and 8 to 9 m (26.2 to 29.5 ft) deep in most parts, and is thus easily navigable except when it freezes over in the winter. However, there are several spots where the river narrows to less than half a kilometre (0.3 mi) and flows quickly, such as at the Sans Sault Rapids at the confluence of the
Mountain RiverThe Mountain River is a tributary of the Mackenzie River in Canada’s Northwest Territories. Its source is in the Mackenzie Mountains close to the watershed border with Yukon Territory. It flows eastward, joining the Mackenzie River just south of the Arctic Circle...
and "The Ramparts", a 40 m (131.2 ft) deep canyon south of
Fort Good HopeFort Good Hope is a charter community in the Sahtu Region of the Northwest Territories, Canada. It is located on a peninsula between Jackfish Creek and the east bank of the Mackenzie River, about 145 km northwest of Norman Wells. The two principal languages are North Slavey and English...
.
Watershed
At 1805200 square kilometres (696,991.6 sq mi), the Mackenzie River's
watershed-Hydrology and geomorphology:* Watershed: drainage divide - * Watershed: drainage basin - -Medical:* Watershed area , an area with overlapping blood supply...
or drainage basin is the largest in Canada, encompassing nearly 20% of the country. From its farthest headwaters at
Thutade LakeThutade Lake is located in the Omineca Mountains of the Northern Interior of British Columbia, Canada. About 40 km in length, and no more than about 2 km wide, the lake is primarily significant as the ultimate source of the Mackenzie River. The lake is at the head of the Finlay River,...
in the
Omineca MountainsThe Omineca Mountains, also known as "the Ominecas", are a group of remote mountain ranges in north-central British Columbia, Canada. They are bounded by the Finlay River on the north, the Rocky Mountain Trench on the east, the Nation River on the south, and the upper reaches of the Omineca River...
to its mouth, the Mackenzie stretches for 4241 km (2,635.2 mi) across western Canada, making it the longest river system in the nation and the thirteenth longest in the world. The river discharges more than 325 cubic kilometres (78 cu mi) of water each year, accounting for roughly 11% of the total river flow into the Arctic Ocean. The Mackenzie's outflow holds a major role in the local climate above the Arctic Ocean with large amounts of warmer fresh water mixing with the cold seawater.
Many major watersheds of North America border on the drainage of the Mackenzie River. Much of the western edge of the Mackenzie basin runs along the Continental Divide. The divide separates the Mackenzie watershed from that of the
Yukon RiverThe 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...
and its headstreams the
PellyThe Pelly River is a river in Canada, and is a headstream of the Yukon River. The river originates west of the Mackenzie Mountains and flows 530 km long through the south central Yukon. The Pelly has two main tributaries, the Ross and Macmillan rivers.The river was named by Robert Campbell in...
and
StewartThe Stewart River is a long river in the Yukon Territory of Canada. It originates in the Selwyn Mountains, which stand on the border between the Northwest Territories and the Yukon Territory. From there, the Stewart flows west, past the village of Mayo...
rivers, which flow to the
Bering StraitThe Bering Strait , known to natives as Imakpik, is a sea strait between Cape Dezhnev, Chukotka Autonomous Okrug, Russia, the easternmost point of the Asian continent and Cape Prince of Wales, Alaska, USA, the westernmost point of the North American continent, with latitude of about 65°40'N,...
; and the
Fraser RiverThe 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...
and
Columbia RiverThe 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...
systems, both of which run to the
Pacific OceanThe 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...
. Lowland divides in the north distinguish the Mackenzie basin from those of the
AndersonAnderson River may refer to:*Anderson River in the United States*Anderson River in Canada*Anderson River in Canada...
,
HortonThe Horton River is a river in northern New South Wales, Australia.The Horton River drains most of the northern slopes of the Nandewar Range. The headwaters of the river are located north of the town of Barraba...
,
CoppermineThe Coppermine River is a river in the North Slave and Kitikmeot regions of the Northwest Territories and Nunavut in Canada. It is long. It rises in Lac de Gras, a small lake near Great Slave Lake and flows generally north to Coronation Gulf, an arm of the Arctic Ocean...
and
BackThe Back River , is a river in the Northwest Territories and Nunavut in Canada...
Rivers – all of which empty into the Arctic. Eastern watersheds bordering on that of the Mackenzie include those of the
ThelonThe Thelon River stretches across northern Canada. Its source is Whitefish Lake in the Northwest Territories, and it flows east to Baker Lake in Nunavut. The Thelon ultimately drains into Hudson Bay at Chesterfield Inlet.-Geography:...
and
ChurchillThe Churchill River is a major river in Alberta, Saskatchewan and Manitoba, Canada. From the head of the Churchill Lake it is 1,609 km long. It was named after John Churchill, 1st Duke of Marlborough and governor of the Hudson's Bay Company from 1685 to 1691...
Rivers, both of which flow into
Hudson BayHudson 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,...
. On the south, the Mackenzie watershed borders that of the
North Saskatchewan RiverThe North Saskatchewan River is a glacier-fed river that flows east from the Canadian Rockies to central Saskatchewan. It is one of two major rivers that join to make up the Saskatchewan River....
, part of the
Nelson RiverThe Nelson River is a river of north-central North America, in the Canadian province of Manitoba. Its full length is , it has mean discharge of , and has a drainage basin of , of which is in the United States...
system, which empties into Hudson Bay after draining much of south-central Canada.
Through its many tributaries, the Mackenzie River basin covers portions of five
Canadian provinces and territoriesThe provinces and territories of Canada combine to make up the world's second-largest country by area. There are ten provinces and three territories...
–
British ColumbiaBritish Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
(BC),
AlbertaAlberta 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...
,
SaskatchewanSaskatchewan 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....
, and the Yukon and Northwest Territories. The two largest headwaters forks, the
PeaceThe Peace River is a river in Canada that originates in the Rocky Mountains of northern British Columbia and flows to the northeast through northern Alberta. The Peace River flows into the Slave River, a tributary of the Mackenzie River. The Mackenzie is the 12th longest river in the world,...
and
AthabascaThe Athabasca River originates from the Columbia Glacier of the Columbia Icefield in Jasper National Park in Alberta, Canada...
Rivers, drain much of the central Alberta prairie and the
Rocky MountainsThe 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...
in northern BC then combine into the
Slave RiverThe Slave River is a Canadian river that flows from Lake Athabasca in northeastern Alberta and empties into Great Slave Lake in the Northwest Territories....
at the
Peace-Athabasca DeltaThe Peace–Athabasca Delta is a large freshwater, inland delta in northeastern Alberta located where the Peace and Athabasca Rivers join the Slave River at the western end of Lake Athabasca.-Conservation :...
near
Lake AthabascaLake Athabasca is located in the northwest corner of Saskatchewan and the northeast corner of Alberta between 58° and 60° N.-History:The name in the Dene language originally referred only to the large delta formed by the confluence the Athabasca River at the southwest corner of the lake...
, which also receives runoff from northwestern Saskatchewan. The Slave is the primary feeder of Great Slave Lake (contributing about 77% of the water); other inflows include the
TaltsonThe Taltson River is a roughly river in the Northwest Territories of Canada. It flows into the Great Slave Lake and ultimately reaches the Beaufort Sea through the Mackenzie River. Eight reservoirs, Nonacho, Taltson, King, Lady Grey, Benna Thy, Kozo, Twin Gorges, and Tsu, impound the river to...
, Lockhart and
Hay RiverHay River is a large river in northern Alberta and southern Northwest Territories, Canada.It originates in the muskeg of north western Alberta, flows west to British Columbia, then returns to Alberta, where it follows a northern course towards the Northwest Territories, where it discharges in the...
s, the latter of which also extends into Alberta and BC. Direct tributaries of the Mackenzie from the west such as the Liard and Peel Rivers carry runoff from the mountains of the eastern Yukon.
The eastern portion of the Mackenzie basin is dominated by vast reaches of lake-studded boreal forest and includes many of the largest lakes in North America. By both volume and surface area,
Great Bear LakeGreat Bear Lake is the largest lake entirely within Canada , the third or fourth largest in North America, and the seventh or eighth largest in the world...
is the biggest in the watershed and third largest on the continent, with a surface area of 31153 km² (12,028.2 sq mi) and a volume of 2236 km³ (536.4 cu mi). Great Slave Lake is slightly smaller, with an area of 28568 km² (11,030.2 sq mi) and containing 2088 km³ (500.9 cu mi) of water, although it is significantly deeper than Great Bear. The third major lake, Athabasca, is less than a third that size with an area of 7800 km² (3,011.6 sq mi). Six other lakes in the watershed cover more than 1000 km² (386.1 sq mi), including the
Williston LakeWilliston Lake is a reservoir created by the W. A. C. Bennett Dam and is located in the Northern Interior of British Columbia, Canada.-Geography:...
reservoirA 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...
, the second-largest artificial lake in North America, on the Peace River.
With an average annual flow of 9910 m3/s, the Mackenzie River has the highest discharge of any river in Canada and is the fourteenth largest in the world in this respect. About 60% of the water comes from the western half of the basin, which includes the Rocky,
SelwynThe Selwyn Mountains are a mountain range in northern Canada, forming part of the border between the Yukon Territory and the Northwest Territories, and which are part of the Eastern System of the Canadian Cordillera . They are neighboured on the east by the Mackenzie Mountains and on their...
, and
MackenzieThe Mackenzie Mountains are a mountain range forming part of the Yukon-Northwest Territories boundary between the Liard and Peel rivers. The range is named in honour of Canada's second Prime Minister Alexander Mackenzie. Nahanni National Park Reserve is in the Mackenzie Mountains.The Mackenzie...
mountain ranges out of which spring major tributaries such as the Peace and Liard Rivers, which contribute 23% and 27% of the total flow, respectively. In contrast the eastern half, despite being dominated by marshland and large lakes, provides only about 25% of the Mackenzie's discharge. During peak flow in the spring, the difference in discharge between the two halves of the watershed becomes even more marked. While large amounts of snow and glacial melt dramatically drive up water levels in the Mackenzie's western tributaries, large lakes in the eastern basin retard springtime discharges. Breakup of ice jams caused by sudden rises in temperature – a phenomenon especially pronounced on the Mackenzie – further exacerbate flood peaks. In full flood, the Peace River can carry so much water that it inundates its delta and backs upstream into Lake Athabasca, and the excess water can only flow out after the Peace has receded.
Geology
As recently as the end of the last glacial period eleven thousand years ago the majority of northern Canada was buried under the enormous continental
Laurentide ice sheetThe Laurentide Ice Sheet was a massive sheet of ice that covered hundreds of thousands of square miles, including most of Canada and a large portion of the northern United States, multiple times during Quaternary glacial epochs. It last covered most of northern North America between c. 95,000 and...
. The tremendous erosive powers of the Laurentide and its predecessors, which at maximum extent completely buried the Mackenzie River valley under thousands of meters of ice and flattened the eastern portions of the Mackenzie watershed. When the ice sheet receded for the last time, it left a 1100 km (683.5 mi)-long postglacial lake called Lake McConnell, of which Great Bear, Great Slave and Athabasca Lakes are remnants. Significant evidence exists that roughly 13,000 years ago, the channel of the Mackenzie was scoured by one or more massive
glacial lake outburst floodA glacial lake outburst flood is a type of outburst flood that occurs when the dam containing a glacial lake fails. The dam can consist of glacier ice or a terminal moraine...
s unleashed from
Lake AgassizLake Agassiz was an immense glacial lake located in the center of North America. Fed by glacial runoff at the end of the last glacial period, its area was larger than all of the modern Great Lakes combined, and it held more water than contained by all lakes in the world today.-Conception:First...
, formed by melting ice west of the present-day
Great LakesThe Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
. At its peak, Agassiz had a greater volume than all present-day freshwater lakes combined. This is believed to have disrupted currents in the Arctic Ocean and led to an abrupt 1,300-year-long cold temperature shift called the
Younger DryasThe Younger Dryas stadial, also referred to as the Big Freeze, was a geologically brief period of cold climatic conditions and drought between approximately 12.8 and 11.5 ka BP, or 12,800 and 11,500 years before present...
.
Ecology
The Mackenzie River's watershed is considered one of the largest and most intact ecosystems in North America, especially in the north. Approximately 63% of the basin – 1137000 km² (438,998.2 sq mi) – is covered by forest, mostly boreal, and wetlands comprise some 18% of the watershed – about 324900 km² (125,444.6 sq mi). More than 93% of the wooded areas in the watershed are virgin forest. There are fifty-three
fishFish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
species in the basin, none of them endemic. Most of the aquatic species in the Mackenzie River are descendants of those of the
Mississippi RiverThe 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...
and its tributaries. This anomaly is believed to have been caused by hydrologic connection of the two river systems during the
Ice AgeAn 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...
s by meltwater lakes and channels.
Fishes in the Mackenzie River proper include the
northern pikeThe northern pike , is a species of carnivorous fish of the genus Esox...
, some
minnowMinnow is a general term used to refer to small freshwater and saltwater fish, especially those used as bait fish or for fishing bait. More specifically, it refers to small freshwater fish of the carp family.-True minnows:...
s, and
lake whitefishThe lake whitefish , also called the Sault whitefish or gizzard fish, is a species of freshwater whitefish from North America. Lake whitefish are found throughout much of Canada and parts of the northern United States, including all of the Great Lakes. A valuable commercial fish, they are also...
, and the river's shores are lined with sparse vegetation like
dwarf birchBetula nana is a species of birch in the family Betulaceae, found mainly in the tundra of the Arctic region.-Description:...
and
willowWillows, 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, as well as numerous peat bogs. Further south the tundra vegetation transitons to black spruce,
aspenPopulus section Populus, of the Populus genus, includes the aspen trees and the white poplar Populus alba. The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by...
and
poplarPopulus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....
forest. Overall, the northern watershed is not very diverse ecologically, due to its cold climate –
permafrostIn geology, permafrost, cryotic soil or permafrost soil is soil at or below the freezing point of water for two or more years. Ice is not always present, as may be in the case of nonporous bedrock, but it frequently occurs and it may be in amounts exceeding the potential hydraulic saturation of...
underlies about three-quarters of the watershed, reaching up to 100 m (328.1 ft) deep in the delta region – and meager to moderate rainfall, amounting to about 410 millimetres (16.1 in) over the basin as a whole. The southern half of the basin, in contrast, includes larger reaches of temperate and alpine forests as well as fertile
floodplainA 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...
and
riparianA 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...
habitat, but is actually home to fewer fish species due to large rapids on the Slave River preventing upstream migration of aquatic species.
Migratory birds use the two major deltas in the Mackenzie River basin – the Mackenzie Delta and the inland Peace-Athabasca Delta – as important resting and breeding areas. The latter is located at the convergence of four major North American migratory routes, or flyways. As recently as the mid-twentieth century, more than 400,000 birds passed through during the spring and up to a million in autumn. Some 215 bird species in total have been catalogued in the delta, including endangered species such as the
whooping craneThe whooping crane , the tallest North American bird, is an endangered crane species named for its whooping sound. Along with the Sandhill Crane, it is one of only two crane species found in North America. The whooping crane's lifespan is estimated to be 22 to 24 years in the wild...
,
peregrine falconThe Peregrine Falcon , also known as the Peregrine, and historically as the Duck Hawk in North America, is a widespread bird of prey in the family Falconidae. A large, crow-sized falcon, it has a blue-gray back, barred white underparts, and a black head and "moustache"...
and
bald eagleThe Bald Eagle is a bird of prey found in North America. It is the national bird and symbol of the United States of America. This sea eagle has two known sub-species and forms a species pair with the White-tailed Eagle...
. Unfortunately, the construction of W.A.C. Bennett Dam on the Peace River has reduced the seasonal variations of water levels in the delta, causing damage to its ecosystems. Populations of migratory birds in the area have steadily declined since the 1960s.
History
The Mackenzie (previously Disappointment) River was named after Alexander Mackenzie, who travelled the river in the hope it would lead to the
Pacific OceanThe 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...
, but instead reached its mouth on the Arctic Ocean on 14 July 1789. In the
DeneThe Dene are an aboriginal group of First Nations who live in the northern boreal and Arctic regions of Canada. The Dené speak Northern Athabaskan languages. Dene is the common Athabaskan word for "people" . The term "Dene" has two usages...
languages it is called
Deh Cho.
The Royal Canadian Mint honoured the 200th anniversary of the naming of the Mackenzie River with the issue of a silver commemorative dollar in 1989.
In 2008, Canadian and Japanese researchers extracted a constant stream of natural gas from a test project at the Mallik methane hydrate field in the Mackenzie Delta. This was the second such drilling at Mallik: the first took place in 2002 and used heat to release methane. In the 2008 experiment, researchers were able to extract gas by lowering the pressure, without heating, requiring significantly less energy. The Mallik gas hydrate field was first discovered by
Imperial OilImperial Oil Limited is Canada's largest petroleum company. The company is engaged in the exploration, production and sale of crude oil and natural gas. It is controlled by US based ExxonMobil, which owns 69.6% of its stock...
in 1971–1972.
Human use
As of 2001, approximately 397,000 people lived in the Mackenzie River basin – representing only 1% of Canada's population. Ninety percent of these people lived in the Peace and Athabasca River drainage areas, and mainly in Alberta. The cold northern
permafrostIn geology, permafrost, cryotic soil or permafrost soil is soil at or below the freezing point of water for two or more years. Ice is not always present, as may be in the case of nonporous bedrock, but it frequently occurs and it may be in amounts exceeding the potential hydraulic saturation of...
regions beyond the Arctic Circle are very sparsely populated, mainly by indigenous peoples. As a result, much of the Mackenzie watershed is comprised by unbroken wilderness and human activities presently little influence on water quality and quantity in the basin's major rivers. Perhaps the heaviest use of the watershed is in resource extraction –
oil and gas in central AlbertaThe Athabasca oil sands are large deposits of bitumen, or extremely heavy crude oil, located in northeastern Alberta, Canada - roughly centred on the boomtown of Fort McMurray...
,
lumberLumber or timber is wood in any of its stages from felling through readiness for use as structural material for construction, or wood pulp for paper production....
in the Peace River headwaters,
uraniumUranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
in Saskatchewan,
goldGold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
in the Great Slave Lake area and
tungstenTungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...
in the Yukon. Especially in the case of oil, these activities are beginning to pose a threat to riverine ecology in the headwaters of the Mackenzie River.
During the ice-free season, the Mackenzie is a major transportation link through the vast wilderness of northern Canada, linking the numerous scattered and isolated communities along its course. Canada's northernmost major
railheadThe word railhead is a railway term with two distinct meanings, depending upon its context.Sometimes, particularly in the context of modern freight terminals, the word is used to denote a terminus of a railway line, especially if the line is not yet finished, or if the terminus interfaces with...
is located at the town of
Hay RiverHay River , known as "the Hub of the North," is a town in the Northwest Territories, Canada, located on the south shore of Great Slave Lake, at the mouth of the Hay River. The town is separated into two sections, a new town and an old town with the Hay River Airport between them...
, on the south shore of Great Slave Lake. Goods shipped there by train and truck are loaded onto barges of the Inuit-owned Northern Transportation Company. Barge traffic travels the entire length of the Mackenzie in long "trains" of up to fifteen vessels pulled by
tugboatA tugboat is a boat that maneuvers vessels by pushing or towing them. Tugs move vessels that either should not move themselves, such as ships in a crowded harbor or a narrow canal,or those that cannot move by themselves, such as barges, disabled ships, or oil platforms. Tugboats are powerful for...
s, with the sole exception being in a few of the river's narrows, where the barges are uncoupled and towed one by one through difficult stretches. Goods are shipped as far as the town of Tuktoyaktuk on the eastern end of the Mackenzie Delta. From there they are further distributed among communities along Canada's Arctic coast and the numerous islands north of it. During the winter, the frozen channel of the Mackenzie River, especially in the delta region, is crisscrossed with
ice roadIce roads are frozen, human-made structures on the surface of bays, rivers, lakes, or seas in the far north. They link dry land, frozen waterways, portages and winter roads, and are usually remade each winter. Ice roads allow temporary transport to areas with no permanent road access...
s served by dogsleds and
snowmobileA snowmobile, also known in some places as a snowmachine, or sled,is a land vehicle for winter travel on snow. Designed to be operated on snow and ice, they require no road or trail. Design variations enable some machines to operate in deep snow or forests; most are used on open terrain, including...
s.
Although the entire main stem of the Mackenzie River is undammed, many of its tributaries and headwaters have been developed for
hydroelectricityHydroelectricity 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...
production,
floodA flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...
control and
agriculturalAgriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
purposes. The W.A.C. Bennett Dam and
Peace Canyon DamThe Peace Canyon Dam is a large hydroelectric dam on the Peace River in northern British Columbia, Canada. It is located southwest of Hudson's Hope, downstream from the W.A.C. Bennett Dam....
on the upper Peace River were completed in 1968 and 1980 for power generation purposes. The two dams, both owned by
BC HydroThe BC Hydro and Power Authority is a Canadian electric utility in the province of British Columbia generally known simply as BC Hydro. It is the main electric distributor, serving 1.8 million customers in most areas, with the exception of the Kootenay region, where FortisBC, a subsidiary of Fortis...
, have a combined capacity of more than 3,400 megawatts (MW). The reservoir of W.A.C. Bennett – Williston Lake – is the largest body of fresh water in BC and the ninth largest man-made lake in the world, with a volume of 70.3 cubic kilometre. Williston's additional purpose of flood control has led to reduced flooding in the Peace River valley, the Peace-Athabasca Delta, and the Slave River, which while providing for better farming conditions, has had significant impacts on wildlife and riparian communities. The decrease in annual flow fluctuations has had impacts as far downstream as the main stem of the Mackenzie.
Agriculture in the Mackenzie River basin is mainly concentrated in the southern portion of the watershed, namely the valleys of the Peace and Athabasca Rivers. The valley of the former river is considered to be some of the best northern farmland in Canada. These conditions are expected to be improved even more by recent trends in climate change, such as warmer temperatures and a longer growing season. It is even said that "there is enough agricultural capability in the Peace River Valley to provide vegetables to all of northern Canada". However, reaches of the Peace River Valley are threatened with flooding by the proposed
Site C DamThe Site C dam is a proposal by the British Columbia Hydro and Power Authority for a large-scale earth fill hydroelectric dam on the Peace River in north-eastern British Columbia, Canada...
, which would generate enough electricity to power about 460,000 households. Site C has been the center of a protracted and ongoing environmental battle since the 1970s, and a decision has not yet been reached as to whether or not to build the dam.
Site C is not the only proposed water project in the Mackenzie basin. A potential
US$The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
1 billion
run-of-the-river hydroelectricityRun-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...
station on the Slave River would generate at least 1,350 MW of power. Some tentative proposals have gone as far as to include dams on the main stem of the Mackenzie itself. By far the largest engineering project ever slated for the Mackenzie River was the
North American Water and Power AllianceThe North American Water and Power Alliance was conceived in the 1950s by the US Army Corps of Engineers as a 'Great Project' to develop more water sources for the United States...
(NAWAPA), a vast series of dams, tunnels and reservoirs designed to move 150 cubic kilometre of Arctic meltwater to southern Canada, the western
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
and
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. The system would involve building massive dams on the Liard, Mackenzie, Peace,
ColumbiaThe 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
FraserThe 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...
rivers, then pumping water into a 650 km (403.9 mi) long reservoir in the
Rocky Mountain TrenchThe Rocky Mountain Trench, or the Trench or The Valley of a Thousand Peaks, is a large valley in the northern part of the Rocky Mountains. It is both visually and cartographically a striking physiographic feature extending approximately from Flathead Lake, Montana, to the Liard River, just south...
. The water would then flow by gravity to irrigate more than 220000 square kilometre in the three countries and generate more than 50,000 MW of surplus energy. First proposed in the 1950s, the project's estimated cost has since risen to over $200 billion. Because of its massive cost and environmental impacts, it is considered unlikely to ever be implemented.
Largest
TributaryA 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...
|
Length |
Watershed |
Discharge |
|
km |
mi |
km2 |
sq mi |
m3/s |
cu ft/s |
| Liard River The Liard River flows through Yukon, British Columbia and the Northwest Territories, Canada. Rising in the Saint Cyr Range of the Pelly Mountains in southeastern Yukon, it flows southeast through British Columbia, marking the northern end of the Rocky Mountains and then curving northeast back...
|
1,115 |
693 |
277,100 |
106,989 |
2,434 |
85,960 |
| North Nahanni River North Nahanni River is a river in the Northwest Territories of Canada. It is a major tributary of the Mackenzie River-Course:The North Nahanni River originates in the Backbone Ranges of the Mackenzie Mountains, at an elevation of . It flows east, south of the Thundercloud Range, then turns...
|
200 |
124 |
|
|
|
|
| Root River |
220 |
138 |
|
|
|
|
| Redstone River The Redstone River is a large river in the Northwest Territories of Canada. It is about long. It is a tributary of the Mackenzie River, joining it on the left bank some north of Wrigley...
|
289 |
180 |
16,400 |
6,332 |
417 |
14,726 |
| Keele River The Keele River is a tributary of the Mackenzie River, about long, in the western part of the Canadian Northwest Territories. Flowing in a generally northeast direction, it drains a sparsely populated, rugged area of the Mackenzie Mountains.-Course:...
|
410 |
255 |
19,000 |
7,340 |
600 |
21,200 |
| Great Bear River The -long Great Bear River, which drains the Great Bear Lake westward through marshes into the Mackenzie River, forms an important transportation link during its four ice-free months. It originates at south-west bay of the lake. The river has irregular meander pattern wide channel with average depth...
|
113 |
70 |
156,500 |
60,425 |
528 |
18,646 |
| Mountain River The Mountain River is a tributary of the Mackenzie River in Canada’s Northwest Territories. Its source is in the Mackenzie Mountains close to the watershed border with Yukon Territory. It flows eastward, joining the Mackenzie River just south of the Arctic Circle...
|
370 |
230 |
13,500 |
5,212 |
123 |
4,344 |
| Arctic Red River The Arctic Red River is the name of a tributary to the Mackenzie River in the Northwest Territories, Canada.In 1993 the river was designated as part of the Canadian Heritage Rivers System. It was also the name of a community on the Mackenzie where the river joins, now known as Tsiigehtchic...
|
500 |
311 |
22,000 |
8,494 |
161 |
5,690 |
Peel RiverThe Peel River is a tributary of the Mackenzie River in the Yukon and Northwest Territories in Canada. Its source is in the Ogilvie Mountains in the central Yukon at the confluence of the Ogilvie River and Blackstone River...
|
580 |
360 |
28,400 |
10,965 |
689 |
24,332 |
Full list
| Tributary | Coordinates |
Great Slave LakeGreat Slave Lake is the second-largest lake in the Northwest Territories of Canada , the deepest lake in North America at , and the ninth-largest lake in the world. It is long and wide. It covers an area of in the southern part of the territory. Its given volume ranges from to and up to ...
|
61.19994°N 116.68219°W |
| Kakisa River Kakisa River is a river in the Northwest Territories of Canada. It is a major tributary of the Mackenzie River.The river gives the name to the Kakisa Formation, a stratigraphical unit of the Western Canadian Sedimentary Basin.-Course:...
|
61.06888°N 117.16782°W |
| Horn River The Horn River is a river in the Northwest Territories of Canada. It is a major tributary of the Mackenzie River.The river gives the name to the Horn River Formation, a shale deposit of the Western Canadian Sedimentary Basin...
|
61.47689°N 118.08234°W |
| Bouvier River |
61.23230°N 119.03584°W |
| Redknife River The Redknife River is a river in the Northwest Territories of Canada. It is a major tributary of the Mackenzie River.The Redknife Formation, a stratigraphical unit of the Western Canadian Sedimentary Basin was named for the river.-Course:...
|
61.22446°N 119.36891°W |
| Trout River Trout River is a river in the Northwest Territories of Canada. It is a major tributary of the Mackenzie River.The river gives the name to the Trout River Formation, a stratigraphical unit of the Western Canadian Sedimentary Basin.-Course:...
|
61.30423°N 119.84453°W |
| Jean Marie River |
61.53288°N 120.63469°W |
| Spence River |
61.58009°N 120.67331°W |
| Rabbitskin River |
61.78209°N 120.69758°W |
| Liard River The Liard River flows through Yukon, British Columbia and the Northwest Territories, Canada. Rising in the Saint Cyr Range of the Pelly Mountains in southeastern Yukon, it flows southeast through British Columbia, marking the northern end of the Rocky Mountains and then curving northeast back...
|
61.85037°N 121.30185°W |
| Harris River |
61.87277°N 121.32580°W |
| Martin River |
61.92633°N 121.57814°W |
| Trail River |
62.10005°N 122.19286°W |
| North Nahanni River North Nahanni River is a river in the Northwest Territories of Canada. It is a major tributary of the Mackenzie River-Course:The North Nahanni River originates in the Backbone Ranges of the Mackenzie Mountains, at an elevation of . It flows east, south of the Thundercloud Range, then turns...
|
62.24562°N 123.32874°W |
| Root River |
62.43685°N 123.31020°W |
| Willowlake River |
62.69863°N 123.1148°W |
| River Between Two Mountains |
62.93655°N 123.21081°W |
| Wrigley River |
63.24410°N 123.58691°W |
| Ochre River |
63.46801°N 123.68962°W |
| Johnson River |
63.71486°N 123.91245°W |
| Blackwater River |
63.94386°N 124.17194°W |
| Dahadinni River |
63.98472°N 124.37399°W |
| Saline River |
64.29422°N 124.49947°W |
| Redstone River The Redstone River is a large river in the Northwest Territories of Canada. It is about long. It is a tributary of the Mackenzie River, joining it on the left bank some north of Wrigley...
|
64.28701°N 124.55492°W |
| Keele River The Keele River is a tributary of the Mackenzie River, about long, in the western part of the Canadian Northwest Territories. Flowing in a generally northeast direction, it drains a sparsely populated, rugged area of the Mackenzie Mountains.-Course:...
|
64.41662°N 124.80005°W |
| Great Bear River The -long Great Bear River, which drains the Great Bear Lake westward through marshes into the Mackenzie River, forms an important transportation link during its four ice-free months. It originates at south-west bay of the lake. The river has irregular meander pattern wide channel with average depth...
|
64.90671°N 125.60034°W |
| Little Bear River |
64.91581°N 125.90435°W |
| Carcajou River |
65.62446°N 128.71682°W |
| Mountain River The Mountain River is a tributary of the Mackenzie River in Canada’s Northwest Territories. Its source is in the Mackenzie Mountains close to the watershed border with Yukon Territory. It flows eastward, joining the Mackenzie River just south of the Arctic Circle...
|
65.67409°N 128.83856°W |
| Donnelly River |
65.82613°N 128.84869°W |
| Tsintu River |
66.13182°N 129.04099°W |
| Hare Indian River |
66.29391°N 128.62381°W |
| Loon River |
66.46969°N 128.97091°W |
| Tieda River |
66.62877°N 129.32616°W |
| Gillis River |
66.72907°N 129.79042°W |
| Gossage River |
66.99237°N 130.26712°W |
| Thunder River |
67.47803°N 130.90673°W |
| Tree River |
67.25315°N 132.57030°W |
| Rabbit Hay River |
67.22483°N 132.76102°W |
| Arctic Red River The Arctic Red River is the name of a tributary to the Mackenzie River in the Northwest Territories, Canada.In 1993 the river was designated as part of the Canadian Heritage Rivers System. It was also the name of a community on the Mackenzie where the river joins, now known as Tsiigehtchic...
|
67.44700°N 133.74743°W |
Peel RiverThe Peel River is a tributary of the Mackenzie River in the Yukon and Northwest Territories in Canada. Its source is in the Ogilvie Mountains in the central Yukon at the confluence of the Ogilvie River and Blackstone River...
|
67.69665°N 134.53102°W |
| Rengleng River |
67.80485°N 134.07145°W |
See also
- List of rivers of Canada
- List of rivers of the Northwest Territories
- Peace River Country
The Peace River Country is an aspen parkland region around the Peace River in Canada. It spans from northwestern Alberta to the Rocky Mountains in northeastern British Columbia, where the region is also referred to as the Peace River Block.- Geography :The Peace River Country includes the...
External links