The Missouri River is a river in the Central and Mountain West regions of the United States.

Oct 31, 2025 · Overview of the Missouri River, the longest tributary of the Mississippi River and second longest river in North America

It begins in southern Montana in the Rocky Mountains, first flowing north then generally southeast across the heart of the United States, ending at the Mississippi River, just to the north of St. Louis, …

The Missouri River will travel more than 2,300 miles before it joins the Mississippi in its namesake state at St. Louis, forming the world’s fourth longest river system as it rolls south to the Gulf of Mexico.

The Missouri River in the United States is the longest tributary of the Mississippi River. Lewis and Clark determined in 1805 that the Missouri begins at the confluence of the Madison, Jefferson, and Gallatin …

Jun 19, 2025 · Spanning over 2,300 miles, it is the longest river in the United States, originating in the Rocky Mountains of southwestern Montana and flowing all the way to its confluence with the …

Jul 8, 2025 · Explore the Missouri River: its map, amazing history, why it's called 'Big Muddy,' and key facts about North America's longest river.

The Missouri is the longest river in the United States, flowing more than 2,500 miles from its source on the eastern slope of the Rockies near Three Forks, Montana, to its confluence with the Mississippi …

The Missouri River is the longest river in North America, stretching about 3,767 kilometers (2,341 miles). It begins in the Rocky Mountains of Montana, flows eastward through seven U.S. states, and …

The Missouri River is a river in the Central and Mountain West regions of the United States. The nation's longest, it rises in the eastern Centennial Mountains ...