The Little Osage River is an 88 miles (141.6 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 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...

 in eastern 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 western 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 Osage 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 Little Osage rises in Kansas in southeastern Anderson

Anderson County, Kansas

Anderson County is a county located in East Central Kansas, in the Central United States. As of the 2010 census, the county population was 8,102...

 and northeastern Allen

Allen County, Kansas

Allen County is a county located in southeast Kansas, in the central United States of America. As of the 2010 census, the county population was 13,371...

 counties as three short streams, the North, Middle and South Forks. The forks converge in northwestern Bourbon County

Bourbon County, Kansas

Bourbon County is a county located in Southeast Kansas, in the Central United States. As of the 2010 census, the county population was 15,173...

, and the river flows generally eastward past Fulton

Fulton, Kansas

Fulton is a city in Bourbon County, Kansas, United States. The population was 184 at the 2000 census.-History:During the American Civil War, Fort Lincoln was built and operated near Fulton as part of the Fort Scott defense, mostly as a prisoner-of-war camp...

 into Vernon County, Missouri, where it passes Stotesbury

Stotesbury, Missouri

Stotesbury is a village in Vernon County, Missouri, United States. The population was 43 at the 2000 census, at which time it was a town.-Geography:Stotesbury is located at , along the Little Osage River....

 and collects the Marmaton River

Marmaton River

The Marmaton River is a tributary of the Little Osage River in southeastern Kansas and western Missouri in the United States...

. On the boundary of Vernon and Bates

Bates County, Missouri

Bates County is a county located in the U.S. state of Missouri. As of 2000, the population is 16,653. Its county seat is Butler. The county was organized in 1833 and named after Frederick Bates, the second governor of Missouri....

 counties, the Little Osage joins the Marais des Cygnes River

Marais des Cygnes River

The Marais des Cygnes River is a principal tributary of the Osage River, about long, in eastern Kansas and western Missouri in the United States. Via the Osage and Missouri rivers, it is part of the watershed of the Mississippi River...

 to form the Osage River, 6 miles (10 km) west of Schell City

Schell City, Missouri

Schell City is a city in Vernon County, Missouri, United States. The population was 286 at the 2000 census.-Geography:Schell City is located at ....

.