Where does the missouri river start?

Missouri River. The Missouri River is the longest river in North America. Rising in the Rocky Mountains of western Montana, the Missouri flows east and south for 2,341 miles (3,767 km) before entering the Mississippi River north of St. Louis, Missouri. read more

The Missouri River begins near Three Forks, Montana, and runs until it merges with the Mississippi River near St. Louis, Missouri. The Missouri River stretches out across 2,341 miles. read more

The Missouri was named Peki-tan-oui on some early French maps and, later, Oumessourit; it has been nicknamed “Big Muddy” because of the amount of solid matter it carries in suspension. For millennia, the area around the upper Missouri River was home to Native American peoples such as the Blackfeet, Hidatsa, and Crow. read more