The Blackwater River is a 79.3 miles (127.6 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 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...

 in west-central 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...

 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 Lamine and Missouri

Missouri River

The Missouri River flows through the central United States, and is a tributary of the Mississippi River. It is the longest river in North America and drains the third largest area, though only the thirteenth largest by discharge. The Missouri's watershed encompasses most of the American Great...

 rivers, it is part of the 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...

 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...

.

Course

The Blackwater River is formed by short north and south forks in Johnson County

Johnson County, Missouri

Johnson County is a county located in the U.S. state of Missouri. As of 2010, the population was 52,595. Its county seat is Warrensburg. The county was formed 13 December 1834 from Lafayette County and was named for Vice President Richard M...

 about 6 miles (10 km) northwest of Warrensburg

Warrensburg, Missouri

Warrensburg is a city in Johnson County, Missouri, United States. The population was 16,340 at the 2000 census. It is the county seat of Johnson County. The Warrensburg Micropolitan Statistical Area consists of Johnson County. It is home to the University of Central Missouri.-History:Warrensburg...

 and flows generally east-northeastwardly through Johnson, Pettis

Pettis County, Missouri

Pettis County is a county located in the U.S. state of Missouri. The county was organized in 1833 and is named for U.S. Congressman Spencer Darwin Pettis. As of 2000, the population was 39,403...

, Saline and Cooper

Cooper County, Missouri

Cooper County is a county located in the U.S. state of Missouri. In 2010, the population was 17,601. Its county seat is Boonville. The county was organized in 1818 and is named for Sarshall Cooper, a frontier settler who was killed by Indians near Arrow Rock in 1814.-Geography:According to the 2000...

 counties, past the towns of Sweet Springs

Sweet Springs, Missouri

Sweet Springs is a city in Saline County, Missouri, along the Blackwater River. The population was 1,628 at the 2000 census.-Geography:Sweet Springs is located at...

 and Blackwater

Blackwater, Missouri

Blackwater is a city in Cooper County, Missouri, along the Blackwater River. The population was 199 at the 2000 census.-Geography:Blackwater is located at ....

. It flows into the Lamine River in northwestern Cooper County, about 4 miles (6.4 km) southeast of Blackwater.

The North Fork of the Blackwater starts as one to three springs in the southwestern corner of Lafayette County near the small village of Chapel Hill, about 7 miles (11 km) south of Bates City

Bates City, Missouri

is a city in Lafayette County, Missouri, United States. The population was 245 at the 2000 census.-Geography:Bates City is located at .According to the United States Census Bureau, the city has a total area of , all of it land....

 and about 29 miles (46.7 km) southeast of 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...

.

Several sections of the river's upper course have been straightened and channelized.