In 1804, Thomas Jefferson commissioned the Lewis and Clark Expedition up the Missouri River to explore the newly acquired western part of the country after the Louisiana Purchase. This famous expedition resulted in identifying new plants and animals, expanding the fur trade and strengthening U.S. claims to the Pacific. From there, cities and towns sprouted on its banks and grew into thriving communities.

As one of the Great 8 landmarks, it’s a must-see on a South Dakota trip. The towns of Chamberlain and Oacoma, Mobridge, Pierre and Winner are great stops with unique offerings along the way. Discover why the mighty Missouri is so important — to South Dakota and the entire United States. While nothing beats sitting on its powerful banks in person, here are some fun facts about the Missouri River.

Facts About the Missouri River

How long is the Missouri River?

At 2,341 miles, the Missouri River is America’s longest, followed by the Mississippi, Yukon, Rio Grande and Colorado rivers.

Where does the Missouri River start and end?

The Missouri River starts west of Bozeman, Montana, where the Gallatin, Jefferson and Madison rivers converge at Three Forks. It then travels more than 2,300 miles before joining the Mississippi in St. Louis, Missouri, and rolling south toward the Gulf of Mexico.

How deep is the Missouri River?

The depth of the Missouri River ranges from 10 to 20 feet, though depth sharply decreases outside of the channel.

Where does the Missouri River meet the Mississippi River?

Approximately 15 miles upstream of St. Louis, on the border between Missouri and Illinois.

Where are the headwaters of the Missouri River?

The headwaters are just west of Bozeman, Montana, where the Jefferson, Madison and Gallatin Rivers converge at Three Forks.

Which states does the Missouri River run through?

Montana, North Dakota, Nebraska, Iowa, Kansas, Missouri and, most importantly, South Dakota.

Which South Dakota reservoirs are part of the Missouri River?

Lake Oahe, Lake Sharpe, Lewis and Clark Lake, and Lake Francis Case are all part of the Missouri River. Thanks to dams near Pierre, Fort Thompson, Pickstown and Yankton, four large reservoirs exist along the length of the Missouri River, offering excellent fishing, boating, jet-skiing, sailing and more.

What kind of wildlife lives in the South Dakota regions of the Missouri River?

You’ll find a wide variety of wildlife year-round in South Dakota’s Missouri River region, from ring-necked pheasants and bald eagles to badgers, beavers and herds of buffalo and deer.

What is a nickname for the Missouri River?

The Missouri River has long been nicknamed “Big Muddy” because of the enormous amount of dirt and rock sediment it pushes through the river system.

Plan Your Trip

A trip to South Dakota isn’t complete without visiting the Missouri River. Camp and hike at Lewis and Clark Recreation Area or take a scenic drive on the Native American National & State Scenic Byway. Come get mighty in South Dakota!