Missouri River

N.P. Dodge Park, Omaha, Nebraska

The Missouri River is one of the Mississippi River's largest tributaries. With its headwaters originating in the mountains of Montana and continuing through its confluence with the Mississippi River just north of Saint Louis, Missouri on down to the Gulf of Mexico, it is the third longest river in the world after the Nile River and the Amazon River.

The Lewis and Clark Expedition explored the new Louisiana Purchase and sought a route to the Pacific Ocean by travelling up the Missouri River.

The Missouri River flows through or at the frontier of the following states: Montana, North Dakota, South Dakota, Nebraska, Iowa, Kansas, and Missouri.

See also: Geography of the United States