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 3,767 kilometers (2,341 miles) before entering the Mississippi River north of St. Louis, Missouri.
The Missouri is the world’s 15th-longest river.
When combined with the lower Mississippi River, it forms the world’s 4th longest river system.
The Missouri drainage area is 1,371,000 square kilometers (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 River flows through several states including Montana, North Dakota, and South Dakota. It flows past Iowa, Nebraska, Missouri, and Kansas.
The name ‘Missouri’ is derived from the Missouri tribe name, meaning ‘people with wooden canoes‘.
The Missouri has the nickname “Big Muddy,” because of the large amount of silt that it carries.
For over 12,000 years, people have depended on the Missouri River and its tributaries as a source of sustenance and transportation.
More than ten major groups of Native Americans populated the watershed, most leading a nomadic lifestyle and dependent on enormous buffalo herds that once roamed through the Great Plains.
The Missouri was formed about 30 million years ago. However, the present course was formed about 115,000 years ago when streams from the Rocky Mountains were diverted by glaciers.
Over 95 significant tributaries and hundreds of smaller ones feed the Missouri River. Major tributaries to the Missouri River include Yellowstone River, Platte River, and Kansas River.
By discharge, the Missouri is the 9th largest river of the United States, after the Mississippi, St. Lawrence, Ohio, Columbia, Niagara, Yukon, Detroit, and St. Clair.
There are approximately 150 fish species in the Missouri River, and about 300 species of birds live in the Missouri River’s region.
The first Europeans to see the Missouri River were the Frenchmen Father Jacques Marquette and Louis Joliet, in 1673, when floating down the Mississippi.
The Missouri River was one of the main routes for the westward expansion of the United States during the 19th century.
Steamboats were a popular means of transport along the river during the early 19th century. One of the steamboats, the Arabia, was buried under (12 meters) 40 feet of mud and remained missing for over a century before being found 0.8 kilometers (half a mile) from the present course of the river.
During the 20th century, the Missouri River basin was extensively developed for irrigation, flood control and the generation of hydroelectric power.
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.
Along the South Dakota and Nebraska border is a more than 160 kilometers (100 miles) long area designated as The Missouri National Recreation Area, where people can boat, fish, and enjoy other water activities.
The Missouri was long believed to be part of the Northwest Passage – a water route from the Atlantic to the Pacific – but when Lewis and Clark became the first to travel the river’s entire length, they confirmed the mythical pathway to be no more than a legend.
The river can be followed by walking along the Lewis and Clark historic trail, which follows the entire length of the river. There are about 100 historic sites along the trail.
Some of the historical landmarks along the Missouri River include Fort Benton-Montana [pic. below], Big Hidatsa Village Site, and Three Forks of Missouri.
Many National Parks in the United States are located in the Missouri River’s watershed, including Glacier National Park, Yellowstone National Park, Badlands National Park, and Rocky Mountain National park.
The World Wide Fund For Nature (WWF) divides the Missouri River watershed into three freshwater ecoregions: the Upper Missouri, Lower Missouri and Central Prairie.
For most of its course, the Missouri flows across the Great Plains, one of the driest parts of North America.