---

 

The Missouri River

On This Site

• The 25 Longest Rivers in the World • The River as a Lifeline • The River as a Boundary • Geography links

Share This Page Follow This Site

---

The Missouri is the world's 15th-longest river at 2,341 miles. It flows from its source, at the Gallatin, Madison, and Jefferson Rivers in Montana, to the Mississippi River, at St. Louis.

The Missouri drainage area is 529,350 square miles, one-sixth of the entire United States. The basin is home to about 10 million people from 28 Native American tribes, 10 states, and a small part of Canada.

The Missouri is one of the most changed rivers in the U.S. Its many dams and reservoirs have created many lakes and stopped the free-flowing nature of the river, stopping flooding in many areas. Historically, the river has changed its course slightly many times in just the 200 years that Americans have been living nearby. In some places, the river has relocated more than 2,000 feet of soil. This is one reason that the Missouri is called the "Big Muddy" and the "Muddy Mo." ("Mo" is short for Missouri.)

The first Europeans to see the Missouri River were the Frenchmen Father Jacques Marquette and Louis Joliet, in 1673, when floating down the Mississippi. American explorers Meriwether Lewis and William Clark traveled the length of the Missouri River on their journey west with the Corps of Discovery.

Today, the river is used primarily for commerce, although some river cruises go up and down the "Muddy Mo."

 

 

 Facts About the Missouri River

Length	2,341 miles
Source(s)	Gallatin, Madison, and Jefferson Rivers, Montana
Mouth	Mississippi River, St. Louis
Countries Flows Through	United States
Major Cities Flows By/Through	Bismarck, N.D.; Pierre, S.D.; Omaha, Neb.; Kansas City, Mo.; St. Louis, Mo.
Where Name Comes From	Missouri Native American tribe