Missouri River

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

See also: Mississippi River, United States.