The Missouri River – A Complete Guide

Vanessa Locampo
Last Updated: February 27th, 2023

Flowing from its headwaters in the Rocky Mountains of Southwestern Montana, the Missouri River is the longest river in the United States.

It drifts across Montana, the Dakotas, Nebraska, Iowa, Kansas, and Missouri, where it meets the Mississippi River, providing water and sustenance to the Great Plains along the way.

We will take a close look at the Missouri River, and look at everything from its history to its geography:

The Missouri River – A Complete Guide

The Missouri River starts in the Rocky Mountains at Three Forks, Montana. From there it flows approx. 2,342 miles across the United States. It stops in Missouri, from which it gets its name. The Missouri River river covers roughly 500,000 square miles and crosses through two Canadian provinces and through 10 American states.

history of the missouri river

History of the Missouri River

The Missouri River is believed to have first formed approximately 30 million years ago and has undergone countless changes to its course since then. The current course that the river follows is estimated to have formed 115,000 years ago.

Prior to European settlement, Native American peoples lived in the area surrounding the Upper Missouri River. Some of the tribes known to have lived in the area include the Blackfeet, Hidatsa, and Crow. The Missouri River was also used for trade, prayer, and burial by Native American tribes, and it remains a place of spiritual practices and burials.

In 1673, French explorers Jacques Marquette and Louis Jolliet came across the mouth of the Missouri while they were traveling down the Mississippi River. On early French maps, the river was called Peki-tan-oui. Later, it was referred to as Oumessourit.

According to the Missouri River Paddler, the word Ouemessorita comes from the Algonquian dialect. This was the name given to the Shiwere people living along the river of the same name, by the Illinois tribe.

Fur traders began to explore upstream in the early 18th century; notable trading companies who used the river included the Spanish Commercial Company, Saint Louis Missouri Fur Company, Columbia Fur Company, and the Rocky Mountain Fur Company.

But it wasn’t until the Lewis and Clark Expedition between 1804 and 1805 that the river was first explored in its entirety, from mouth to headwaters.

Steamboat traffic began on the river in 1830 with the American Fur Company, which reached its peak in 1858. Paddle steamers also helped settlement in the Dakotas and Montana. In the 1860s, steamboats used the river to provide transportation to mining towns in response to the gold rush, and to farms in Nebraska.

The Missouri River eventually became the gateway to the major trails that opened the American West, including the California, Mormon, Oregon, and Santa Fe Trails. However, due to the Hannibal and St. Joseph Railway, which traveled to St. Joseph, Missouri, steamboat traffic on the Missouri River later declined.

The Hannibal Bridge in Kansas City was the first bridge built across the river in 1869.

While primarily used as transportation to support trade and commercial activities, the Missouri River was still not developed as a major waterway until the mid-20th century. It was also not used as a source of irrigation or power in the first 150 years after settlement.

In 1944, a network of over 100 dams and reservoirs was planned for development in the Missouri River basin. Levees and bank stabilization, for flood protection, and a deeper river channel was put in place between Sioux City, Iowa, and the Mississippi River.

Major dams were soon built on the river, including Fort Peck near Glasgow, Montana, which have reduced flooding and provided irrigation to the cropland along the river and extended tributaries. Throughout the 1950s, commercial barge lines began to operate in Missouri.

Today, the river is a major source of water and hydroelectricity, as well as being a resource for tourism and recreation.

Geography & Stats

geography & stats

Although it’s the longest river in the United States, the Missouri River is actually a tributary of the Mississippi River, the second-longest river in the country.

Its headwaters begin in the Rocky Mountains area of Montana and the course runs for 2,3411 miles (3,767 kilometers) to its ending point.

Overall, the drainage basin of the Missouri River expands 529,400 square miles (1,371,100 square kilometers) of the Great Plains a vast area of grasslands west of the Mississippi River and east of the Rocky Mountains.

The catchment of the Missouri River is comparable in size to one-sixth of the United States or five percent of the North American continent. In total, it is estimated to be around the size of Quebec, Canada.

The headwaters of the Missouri River begin approximately 4,000 feet (1,200 meters) above sea level. The river flows north and northeast through western Montana via Great Falls, before traveling east across the state’s north.

From Montana, the Missouri River enters North Dakota, traveling in a southeastern direction before continuing south. The river passes Bismarck and enters South Dakota, flowing to Pierre.

It continues through South Dakota, forming sections of the South Dakota-Nebraska border, the Nebraska-Iowa border, the Nebraska-Missouri border, and the Kansas-Missouri border.

When the river reaches Kansas City, Missouri, it travels east and then southeast across the state towards Jefferson City. After one final eastward turn, the river flows into the Mississippi River around 10 miles (16 kilometers) north of St. Louis, Missouri.

The primary tributaries of the Missouri River coursing in from the south and west sides are the Cheyenne, Kansas, Niobrara, Osage, Platte, and Yellowstone rivers. The James and Milk rivers flow in from the north, while the Big Sioux, Chariton, Little Platte, Marias, Sun, and Teton rivers enter from the north and east.

The tributaries that flow into the Missouri River from the south and west include the Bad, Blackwater, Cannonball, Gasconade, Grand, Heart, Judith, Knife, Little Missouri, Moreasu, Musselshell, and White rivers.

In some accounts, the upper course of the Jefferson River in Southwestern Montana, the Red Rock River, is counted as part of the Missouri River. This is known as the Missouri-Red Rock River system, which stretches for a total length of 2,540 miles (4,090 kilometers).

The minimum flow of the Missouri River is 4,200 cubic feet (120 cubic meters) per second, while the maximum is 900,000 cubic feet (25,500 cubic meters) per second.

Water pollution in the form of silting and erosion are natural occurrences, with the Missouri River carrying such a high silt load that it has been nicknamed the Big Muddy. However, the major dams on the upper river are able to trap a lot of sediment.

Missouri River Trail points out that while the Missouri River does carry large quantities of dirt and sand, visible in its brown color, it is not actually “dirty”. Research has shown that the Missouri River actually contains water that is comparable to the Lake of the Ozarks in terms of quality.

Activities & Attractions

With torrents of water that are central to life in the Great Plains, the Missouri River is an attraction in itself. But there are also plenty of highlights scattered along and around the river, many of them within the state of Montana.


Missouri Headwaters State Park

missouri headwaters state park

The Missouri Headwaters State Park, just outside of Three Forks, Montana, is where it all begins. The main drawing point to the park is the convergence of the Jefferson, Madison, and Gallatin Rivers, which come together to form the beginning of the great Missouri River.

Spanning 532 acres (215.2 hectares), the park offers 17 campsites, including tipi rental. There are also several interpretive displays dispersed throughout the park, which aim to educate about the natural and cultural history of the area.

There’s no shortage of recreational activities available, from fishing and river floating to bicycling, hiking, photography, picnicking, and interpretive programs.

The park is open all year and entrance fees range from $4 to $8, depending on whether you have a vehicle with you. It is free to enter for Montana residents who pay the $9 state parks fee as part of their annual vehicle registration.

For more information about Missouri Headwaters State Park, please visit the official Montana Fish, Wildlife, and Parks website.

Giant Springs State Park

giant springs state park

Situated just beyond Great Falls, Giant Springs State Park boasts just under 14 miles of Missouri River shoreline.

The park is home to the legendary Giant Springs, one of the largest freshwater springs in the United States. The springs produce more than 156 million gallons of water each day.

Park guests are welcome to dip their feet into the bubbling springs and visit the Giant Springs Fish Hatchery, where they can feed the fish in the show pond. The park is a top destination for picnicking thanks to the mesmerizing scenery composed of silver poplars and fresh green lawn.

Fishing and bird-watching are popular activities in the park, along with biking on the 30+ miles of trail. Lewis and Clark first recorded the Giant Springs in 1805, and the park also features interpretive displays as a testament to the fascinating local history.

For more information about Giant Springs State Park, please visit the official Montana Fish, Wildlife, and Parks website.

Fort Peck Reservoir

fort peck reservoir

The Fort Peck Reservoir is formed by the Fort Peck Dam on the Missouri River. Reaching depths of 220 feet (67 meters) when full, the lake is located 18 miles (28.9 kilometers) southeast of Glasgow, Montana.

Stretching for 134 miles (215.6 kilometers), the lake is a must-visit for fishing enthusiasts. Among the species of fish commonly found in the lake are northern pike, walleye, Chinook salmon, smallmouth bass, lake trout, paddlefish, and sauger. Anglers mostly fish from boats, although shore fishing is available in some areas.

The Fort Peck Dam has a total of 19 recreational areas, attracting visitors seeking a remote experience in the great outdoors. As well as fishing and boating, camping, wildlife viewing and bird watching, hunting, swimming, picnicking, and sightseeing are all popular activities.

For more information about the Fort Peck Reservoir, please visit the official website.

The Upper Missouri River Breaks National Monument

missouri river at sunset

The Upper Missouri River Breaks National Monument consists of 375,000 acres (151, 757 hectares) of public land in central Montana, from the Missouri River to Fort Benton.

Within the Monument are scenic and historic trails and wilderness areas housing distinct flora and fauna together with unique geological formations.

A great location to observe roaming Rocky Mountain bighorn sheep and elk, the Badlands of Upper Missouri feature several hiking opportunities in an area of abundant rugged beauty. There are also frequent sightings of mule deer herds.

The Monument hosts a collection of designated campgrounds along the river, and camping is even permitted at locations that are not organized campgrounds.

The Missouri Breaks Interpretive Center is found in Fort Benton and highlights the rich local history of the Badlands through film viewings, models, and life-size replicas.

For more information about the Upper Missouri River Breaks National Monument, please visit the Friends of the Missouri Breaks Monument’s official website.

The Lewis and Clark Trail

three forks, mt

There are several points on the historic Lewis and Clark Trail that encompass portions of the Missouri River in Montana.

One of the most iconic is the Five Falls of the Missouri, which is actually the amalgamation of five separate waterfalls across 10 miles (16 kilometers).

The Five Falls, some named by the famed explorers, are Great Falls, Crooked Falls, Rainbows (originally named Beautiful Cascade by William Clark), Colter Falls, and Black Eagle Falls (originally named Upper Pitch by Clark).

The Three Forks of the Missouri and the confluence of the Marias and Missouri rivers are other points of the Missouri that feature on the Lewis and Clark Trail, along with some already-mentioned attractions, such as Giant Springs.

For a full list of the Lewis and Clark Trail locations in Montana, many of which are along or in close proximity to the Missouri River, please visit the National Park Service official website.

Charles M. Russell National Wildlife Refuge

Surrounding the Fort Peck Reservoir near Glasgow is the famous Charles M. Russell National Wildlife Refuge. Straddling the shore of the Missouri River, the refuge is iconic for its wildlife; visitors can spot anything in the area from Rocky Mountain elk to red foxes.

The park spans 1,100,000 acres (445, 154 hectares) and is home to mule deer, coyote, mountain bluebirds, osprey, white pelicans, sage grouse, rattlesnakes, and more. The land was once home to the largest wild bison herd on the continent, which the National Wildlife Federation is working to recover.

Visitors will also find stunning landscapes that inspired the work of the artist Charles M. Russell, including prairies, river bottoms, dense forests, and Badlands.

For more information about the Charles M. Russell National Wildlife Refuge, please visit the official U.S. Fish and Wildlife Service website.




When it comes to fishing, Montana is a world-class destination. Several of the best opportunities for angling are found along the Missouri River. Catfish, bass, crappie, walleye, sauger, sturgeon, and many other species are regularly caught in the river.

According to the Montana Angling Co., one of the best locations along the river for fly fishing is the tailwater stretch below Holter Dam. Here, there are more than 5,000 trout per mile, thick hatches, and large pods of rising fish.

The rules tend to vary according to the exact location you’re fishing in, but in most cases, all anglers need a valid fishing license. There are also length and creel limits in place.


The Missouri River has a rich boating tradition, and this is hands-down one of the best ways to experience it. Some areas of the river are calm enough to navigate with a small boat, while other parts will require a larger vessel, such as a powerboat.

There are also narrow portions of the river which are only accessible to small boats, such as kayaks and canoes. Canoeing, in particular, is an extremely popular river pastime as it takes travelers back in time to the days of Lewis and Clark, especially as much of the surrounding landscape hasn’t changed since the 19th century.

Swimming is not encouraged as the strong currents in parts of the river can put swimmers in immediate danger.


There are countless hiking trails to be found in the land surrounding the Missouri River. And many of these lead to peaks that provide unbeatable views of the river itself.

The Missouri Headwaters State Park features a selection of popular hiking trails, as does Giant Springs State Park.

There are also spectacular trails in the Charles M. Russell National Wildlife Refuge, while the most famous trail near the Missouri River is arguably the River’s Edge Trail, which stretches 60 miles from Great Falls, Montana.

Wildlife Watching

The Missouri River isn’t just vital to the survival of humans in the Great Plains it has also nourished a bionetwork of several species of native animals, all of which rely on the river.

The Charles M. Russell National Wildlife Refuge is one of the most famous destinations for animal lovers along the Missouri River. Another is the UL Bend National Wildlife Refuge, which is found in the Missouri River Breaks about 50 miles (80 kilometers) south of Malta.

Some of the most frequently observed wildlife roaming in the area include white-tail deer, mule deer, various bird species, elk, and bighorn sheep.



Camping is the best way to experience the natural beauty of the Missouri River at all hours, from the quiet dawn to the darkest night, when the sky comes alive with stars.

The Missouri Headwaters State Park, which encompasses the very beginning of the river, is one of the best locations for camping.

Campsites within the park range from $4 to $34 per night, while visitors can also stay in tipis for between $26 and $42 per night.

For a full list of campgrounds in Montana’s Missouri River Country, many of them in close proximity to the Missouri River, please visit the region’s official website.

Missouri River Facts

missouri river facts

  • The Missouri River is the 15th-longest river in the world.
  • The Missouri is commonly divided into three freshwater ecoregions: Upper Missouri, Lower Missouri, and Central Prairie.
  • At least 10 major tribes of Native Americans once populated the Missouri watershed.
  • Before Lewis and Clark traveled the river in its entirety, it was widely believed that the Missouri was part of a water route from the Atlantic to the Pacific known as the Northwest Passage. The Expedition proved the waterway to be nothing more than a myth.
  • The Missouri River is fed by 95 tributaries and hundreds of smaller streams.
  • The name “Missouri” is derived from the Missouri Tribe, referring to “wooden canoe people” (Missouri Secretary of State).
  • The elevations within the Missouri Basin range from 14,000 feet in the Rocky Mountains to 400 feet at the Mississippi River (World Atlas).
  • The river’s drainage basin features harsh cold winters and warm wet summers, consistent with a continental climate.
  • There are approximately 150 species of fish residing in the Missouri River. Around 300 species of birds also live in the region.
  • Numerous species of mammals, including minks, river otters, muskrats, raccoons, and beavers live in the Missouri’s riparian and aquatic habitats.
  • Human activity in and around the river since the 19th century has led to the pollution of the river and reduced its water quality.
  • Temperatures in the Missouri River Basin are projected to increase by roughly 5°F – 6°F during the 21st century (U.S. Department of the Interior Bureau of Reclamation).


Is the Missouri River longer than the Mississippi River?

Yes, the Missouri River is the longest river in the United States. It is longer than the Mississippi River by about 100 miles.

What is the Missouri River known for?

Aside from being America’s longest river, the Missouri River is sometimes called the Center of Life for the Great Plains. Throughout history, the river has supported exploration, food, trade, and transportation for millions of people in the area.

Today, the Missouri River is a tourism staple providing the ultimate destination for boating, relaxing, and getting in touch with the great outdoors.

How deep is the Missouri River?

The depth of the Missouri River varies from point to point. The shallowest parts tend to range between 10 and 20 feet deep. However, the river’s deepest point, near New Orleans, is up to 200 feet deep.

How long is the Missouri River?

The Missouri River extends for 2,341 miles (3,767 kilometers), making it the longest river in the United States.

How wide is the Missouri River?

The width of the Missouri River also fluctuates in several places along its 2,431-mile length. In most places, it is 700 feet (213 meters) wide.

The Missouri River has decreased in width by about half since it was channelized.

Where does the Missouri River start?

The Missouri River starts in Missouri Headwaters State Park, near Three Forks, Montana, where the Jefferson, Madison, and Gallatin Rivers meet. This location is at an elevation of around 4,000 feet (1,200 meters) above sea level in the Rocky Mountains.

The three rivers that form the headwaters for the Missouri River begin near Bowers Spring, southwest Montana, and Yellowstone National Park, in Wyoming.

Where does the Missouri River end?

The Missouri River ends just north of St. Louis, Missouri, where it converges with the Mississippi River. Before reaching this point, it crosses several states, including South Dakota, North Dakota, Nebraska, Iowa, and Kansas.

Which way does the Missouri River flow?

The Missouri River flows east and south from the Rocky Mountains of western Montana to the Mississippi River, north of St. Louis, Missouri.

Final Thoughts

The Missouri River has been central to life in the Great Plains for thousands of years. Today, it continues to play a vital role in the natural ecosystem while also supporting the lives of millions of people and providing unrivaled recreation.

Have you ever visited the Missouri River? Let us know in the comments below!

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About The Author

Vanessa Locampo

Vanessa is an Australian-based freelance writer and editor with a BA in Creative Writing. She’s passionate about creating travel content that inspires her readers to take a leap of faith and power through their bucket lists. When she’s not writing (with her border collie asleep at her feet), she’s devouring books, exploring the world, or planning her next trip.

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