The Stillwater River is a 69.3 miles (111.5 km) 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 Great Miami River

Great Miami River

The Great Miami River is a tributary of the Ohio River, approximately long, in southwestern Ohio in the United States...

 in western Ohio

Ohio

Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. Via the Great Miami and 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...

 rivers, it is part 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...

 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...

.

It rises near the Indiana

Indiana

Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...

 state line, in western Darke County

Darke County, Ohio

As of the census of 2000, there were 53,309 people, 20,419 households, and 14,905 families residing in the county. The population density was 89 people per square mile . There were 21,583 housing units at an average density of 36 per square mile...

, approximately 10 miles (16.1 km) northwest of Greenville

Greenville, Ohio

Greenville is a city in Darke County, Ohio, United States. The population was 13,227 at the 2010 census. It is the county seat of Darke County.-History:Greenville is the historic location of Fort Greene Ville,Greenville is a city in Darke County, Ohio, United States. The population was 13,227 at...

. It flows east-southeast and is joined by Greenville Creek

Greenville Creek

Greenville Creek is a tributary of the Stillwater River in southwestern Ohio in the United States. Via the Stillwater River, the Great Miami River, and the Ohio River, its water flows to the Mississippi River and ultimately the Gulf of Mexico. The creek starts in extreme eastern Indiana in...

 in Covington

Covington, Ohio

Covington is a village in Miami County, Ohio, United States. The population was 2,559 at the 2000 census. It is part of the Dayton Metropolitan Statistical Area. The village was incorporated as Covington in 1835...

, approximately 5 miles (8 km) west of Piqua

Piqua, Ohio

Piqua is a city in Miami County, Ohio, United States. The population was 20,738 at the 2000 census. It is part of the Dayton Metropolitan Statistical Area.Piqua was one of the cities that experienced severe flooding during the Great Dayton Flood of 1913....

. It flows south past Covington and Englewood

Englewood, Ohio

Englewood, a northern suburb of Dayton, is a city in Montgomery County, Ohio, United States. The population was 13,465 at the 2010 census. It is part of the Dayton Metropolitan Statistical Area.-History:...

, where it is dammed for flood

Flood

A 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, then southeast to join the Great Miami River in Dayton

Dayton, Ohio

Dayton is the 6th largest city in the U.S. state of Ohio and the county seat of Montgomery County, the fifth most populous county in the state. The population was 141,527 at the 2010 census. The Dayton Metropolitan Statistical Area had a population of 841,502 in the 2010 census...

.

The Miami County village of Ludlow Falls

Ludlow Falls, Ohio

Ludlow Falls is a village in Miami County, Ohio, United States. The population was 210 at the 2000 census. It is part of the Dayton Metropolitan Statistical Area.-Geography:Ludlow Falls is located at ....

 lies on the river. The village's name comes from the waterfall

Waterfall

A waterfall is a place where flowing water rapidly drops in elevation as it flows over a steep region or a cliff.-Formation:Waterfalls are commonly formed when a river is young. At these times the channel is often narrow and deep. When the river courses over resistant bedrock, erosion happens...

 of the river located in the village. The falls are lit up during the Christmas season.

The Stillwater River was one of the Great Miami River tributaries that flooded during the Great Dayton Flood

Great Dayton Flood

The Great Dayton Flood of 1913 flooded Dayton, Ohio, and the surrounding area with water from the Great Miami River, causing the greatest natural disaster in Ohio history...

 of 1913, resulting in the creation of the Miami Conservancy District

Miami Conservancy District

The Miami Conservancy District is a river management agency operating in Southwest Ohio to control flooding of the Great Miami River and its tributaries. It was organized in 1914 following the catastrophic Great Dayton Flood of the Great Miami River in March 1913, which hit Dayton, Ohio...

.

Variant names

According to the Geographic Names Information System

Geographic Names Information System

The Geographic Names Information System is a database that contains name and locative information about more than two million physical and cultural features located throughout the United States of America and its territories. It is a type of gazetteer...

, the Stillwater River has also been known as:

• Jacobs Lateral
• Southwest Branch
• Stillwater Creek