Considered as a separate river, the Missouri is the longest in the United States. In combination with the Mississippi River
into which it flows at St Louis
, it is the longest river system in the U.S. The river begins where the Gallatin River
, Jefferson River
, and Madison River
come together in the foothills of the Rockies in Montana
. It flows through Montana, North Dakota
and South Dakota
, before forming the boundary between Iowa
. It forms the extreme NE border of Kansas
before turning almost due east through the state of Missouri
Major cities on the Missouri include Great Falls MT, Bismarck ND, Pierre SD, Omaha NE and St Joseph, Kansas City and St Louis in Missouri.
The Lewis and Clark Expedition traveled along the Missouri River on their exploration of the West. Much of their route has been lost beneath the reservoirs created by the many dams that have been built on the river.