| Missouri River Big Muddy[1], Mighty Mo, Wide Missouri | |
|---|---|
 The Missouri River near Rocheport, Missouri | |
 Map of the Missouri River and its tributaries in North America | |
| Etymology | The Missouri tribe, whose name in turn meant "people with wooden canoes"[2] |
| Native name | Pekitanoui[2], Kícpaarukstiʾ[3] Lakota: Mnišoše[4][5] Error {{native name checker}}: parameter value is malformed (help) |
| Location | |
| Country | United States |
| States | Montana, North Dakota, South Dakota, Nebraska, Iowa, Kansas, Missouri |
| Cities | Great Falls, MT, Bismarck, ND, Pierre, SD, Sioux City, IA, Omaha, NE, Kansas City, KS, Kansas City, MO, St. Louis, MO, St. Joseph, MO |
| Physical characteristics | |
| Source | Hell Roaring Creek–Red Rock River–Beaverhead River–Jefferson River |
| • location | Brower's Spring, Centennial Mountains, Montana |
| • coordinates | 44°33′02″N 111°28′21″W / 44.55056°N 111.47250°W[6][7] |
| • elevation | 9,100 ft (2,800 m) |
| 2nd source | Firehole River–Madison River |
| • location | Madison Lake, Yellowstone National Park, Wyoming |
| • coordinates | 44°20′55″N 110°51′53″W / 44.34861°N 110.86472°W[8] |
| • elevation | 8,215 ft (2,504 m) |
| Source confluence | Missouri Headwaters State Park |
| • location | Three Forks |
| • coordinates | 45°55′39″N 111°20′39″W / 45.92750°N 111.34417°W[2] |
| • elevation | 4,042 ft (1,232 m) |
| Mouth | Mississippi River |
• location | Spanish Lake, near St. Louis, Missouri |
• coordinates | 38°48′49″N 90°07′11″W / 38.81361°N 90.11972°W[2] |
• elevation | 404 ft (123 m)[2] |
| Length | 2,322 mi (3,737 km)[9] |
| Basin size | 529,350 sq mi (1,371,000 km2)[10] |
| Discharge | |
| • location | Hermann, MO, 97.9 mi (157.6 km) from the mouth |
| • average | 87,890 cu ft/s (2,489 m3/s)[12] |
| • minimum | 602 cu ft/s (17.0 m3/s)[11] |
| • maximum | 750,000 cu ft/s (21,000 m3/s)[13] |
| Basin features | |
| Tributaries | |
| • left | Jefferson River, Dearborn River, Sun River, Marias River, Milk River, James River, Big Sioux River, Grand River, Chariton River |
| • right | Gallatin River, Yellowstone River, Little Missouri River, Cheyenne River, White River, Niobrara River, Platte River, Kansas River, Osage River, Gasconade River |
The Missouri River is a major river of the central United States, and is the longest river in North America. Beginning in the Rocky Mountains of southwestern Montana, the Missouri flows east and south across the Great Plains for 2,322 miles (3,737 km)[9] before joining the Mississippi River near St. Louis, Missouri. Measured to its furthest headwaters, the Missouri is 2,617 miles (4,212 km) long,[9] with a drainage basin of 529,350 square miles (1,371,000 km2) extending into ten U.S. states and two Canadian provinces. The combined Mississippi–Missouri river system is the fourth longest in the world.
Before the Illinoian glaciation over 100,000 years ago the upper Missouri River likely flowed north into Hudson Bay; as massive ice sheets descended from Canada the river was diverted south across the Great Plains towards the Mississippi. The upper course of the Missouri River roughly marks the edge of the ice sheet at its maximum. Due to its path through thick glacial till and other sedimentary layers, the Missouri has a very high natural sediment load, earning it the nickname, the "Big Muddy". Before the construction of dams and levees, it frequently changed course across its wide floodplain, which supported significant wetland and riparian habitats.
Humans first arrived in the Missouri basin about 12,000 years ago, at the end of the last glacial period as the ice retreated. For thousands of years, the Missouri River has been used by Native Americans as a trade route and a territorial boundary. Native peoples depended on hunting the vast bison (buffalo) herds of the surrounding plains, and used riparian vegetation along the Missouri River as winter forage and material to construct dwellings. European explorers first arrived in the 1600s, with both Spain and France laying claims on the region before the US acquired the Missouri basin via the Louisiana Purchase.
The Missouri River was a key route for the United States' western expansion during the 1800s, starting with the Lewis and Clark Expedition and other explorers, mountain men and fur trappers who mapped the region and blazed trails. Settlers and prospectors headed west en masse beginning in the 1830s, traveling up the river by steamboat before embarking overland by covered wagon, and later the railroad. As settlement encroached on Native American lands, armed conflict broke out; it was not until the 1870s when the U.S. army defeated the last native groups and forced them onto reservations.
Construction of hydroelectric dams began on the Missouri River in the 1890s, providing power to mills and mining settlements. Six much larger dams, comprising the Missouri River Mainstem System, were built between the 1930s and 1960s by the U.S. Army Corps of Engineers to enhance navigation and control floods. These and hundreds of smaller irrigation, flood control and water supply projects have heavily modified the Missouri River, with considerable economic benefits but at the cost of the natural environment.
- ^ "Spotlight on the Big Muddy" (PDF). Missouri Stream Team. Archived from the original (PDF) on October 17, 2011. Retrieved January 14, 2012.
- ^ a b c d e "Missouri River". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. 1980-10-24. Retrieved 2010-05-06.
- ^ "AISRI Dictionary Database Search--prototype version. "River", Southband Pawnee". American Indian Studies Research Institute. Retrieved 2012-05-26.
- ^ Karolevitz, Robert F.; Hunhoff, Bernie (1988). Uniquely South Dakota. Donning Company. p. 9. ISBN 978-0-89865-730-2.
- ^ Ullrich, Jan, ed. (2011). New Lakota Dictionary (2nd ed.). Bloomington, IN: Lakota Language Consortium. ISBN 978-0-9761082-9-0. LCCN 2008922508.
- ^ [1] USGS topographic map of the source
- ^ Cite error: The named reference
headwaterswas invoked but never defined (see the help page). - ^ "Madison Lake". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. 1980-04-04. Retrieved 2012-01-21.
- ^ a b c Cite error: The named reference
NHDwas invoked but never defined (see the help page). - ^ Cite error: The named reference
Storywas invoked but never defined (see the help page). - ^ Cite error: The named reference
missouriflowwas invoked but never defined (see the help page). - ^ Cite error: The named reference
NWIS Missouri River Hermannwas invoked but never defined (see the help page). - ^ Pinter, Nicholas; Heine, Reuben A. "Hydrologic History of the Lower Missouri River". Geology Department. Southern Illinois University, Carbondale. Archived from the original on July 23, 2011. Retrieved May 8, 2010.