The Bighorn River is a

tributary A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drai ...

of the

Yellowstone Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowston ...

, approximately long, in the states of

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

and

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columb ...

in the western United States. The river was named in 1805 by fur trader François Larocque for the

bighorn sheep The bighorn sheep (''Ovis canadensis'') is a species of sheep native to North America. It is named for its large horns. A pair of horns might weigh up to ; the sheep typically weigh up to . Recent genetic testing indicates three distinct subspec ...

he saw along its banks as he explored the Yellowstone. The upper reaches of the Bighorn, south of the

Owl Creek Mountains The Owl Creek Mountains are a subrange of the Rocky Mountains in central Wyoming in the United States, running east to west to form a bridge between the Absaroka Range to the northwest and the Bridger Mountains to the east. The range forms the bo ...

in Wyoming, are known as the Wind River. The two rivers are sometimes referred to as the Wind/Bighorn. The Wind River officially becomes the Bighorn River at the Wedding of the Waters, on the north side of the Wind River Canyon near the town of Thermopolis. From there, the river flows through the

Bighorn Basin The Bighorn Basin is a plateau region and intermontane basin, approximately 100 miles (160 km) wide, in north-central Wyoming in the United States. It is bounded by the Absaroka Range on the west, the Pryor Mountains on the north, the Bigho ...

in north central Wyoming, passing through Thermopolis and

Hot Springs State Park Hot Springs State Park is a public recreation area in Thermopolis, Wyoming, known for its hot springs, which flow at a constant temperature of . The state park offers free bathing at the State Bath House, where temperatures are moderated to a th ...

. At the border with Montana, the river turns northeast, and flows past the north end of the

Bighorn Mountains The Bighorn Mountains ( cro, Basawaxaawúua, lit=our mountains or cro, Iisaxpúatahchee Isawaxaawúua, label=none, lit=bighorn sheep's mountains) are a mountain range in northern Wyoming and southern Montana in the United States, forming a ...

, through the

Crow Indian Reservation The Crow Indian Reservation is the homeland of the Crow Tribe. Established 1868, the reservation is located in parts of Big Horn, Yellowstone, and Treasure counties in southern Montana in the United States. The Crow Tribe has an enrolled member ...

, where the Yellowtail Dam forms the Bighorn Lake

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

. The reservoir and the surrounding canyon are part of the

Bighorn Canyon National Recreation Area Bighorn Canyon National Recreation Area is a national recreation area established by an act of Congress on October 15, 1966, following the construction of the Yellowtail Dam by the Bureau of Reclamation. It straddles the border between Wyoming ...

. The Little Bighorn River joins the Bighorn near the town of

Hardin, Montana Hardin is a city in and the county seat of Big Horn County, Montana, United States. The population was 3,818 at the 2020 census. It is located just north of the Crow Indian Reservation. History The city was named for Samuel Hardin, a friend o ...

. Approximately farther downriver, the Bighorn River ends where it joins the Yellowstone.

Course

A108, Bighorn Canyon National Recreation Area, Montana, USA, 2004

The Bighorn River begins as the Wind River in the Rocky Mountains at Wind River Lake, near Two Ocean Mountain and the summit of

Togwotee Pass Togwotee Pass (pronounced TOH-guh-tee) is a high mountain pass in the western United States, at an elevation of above sea level. On the Continental Divide in the Absaroka Mountains of northwestern Wyoming in Teton County, it is betwee ...

. The Wind River flows southeast receiving the east fork of the Wind River from the north, and enters the

Wind River Basin The Wind River Basin or Shoshone Basin is a semi-arid intermontane foreland basin in central Wyoming, United States. It is bounded by Laramide uplifts on all sides. On the west is the Wind River Range and on the North are the Absaroka Range and t ...

, flowing past Dubois and Johnstown, to Riverton, where it receives the Little Wind River. The river then changes direction to the northeast and then the north, flowing into Boysen Reservoir, which is formed by

Boysen Dam The Boysen Dam is a rockfill dam on the Wind River in the U.S. state of Wyoming. The dam lies at the head of Wind River Canyon through the Owl Creek Mountains in western Wyoming and creates Boysen Reservoir. It is owned by the U.S. Bureau of R ...

. Below the dam it enters the

Wind River Canyon Wind River Canyon is a scenic Wyoming canyon on the Wind River. It is located between the towns of Shoshoni and Thermopolis and is a popular stop for visitors to Yellowstone National Park. It is accessible by U.S. Highway 20 and Wyoming Highwa ...

, where the river narrows and forms many rapids. At the end of the canyon the Wind River widens out in an area called the ''Wedding of the Waters'' where it becomes the Bighorn River and enters the

. The Bighorn continues northward, passing through Thermopolis, Worland, and Basin. At Greybull it receives the

Greybull River The Greybull River is a tributary of the Big Horn River, approximately long in northern Wyoming in the United States. The river was reportedly named for a white buffalo that had been seen on its banks. Native Americans consider the appearanc ...

, and about north of that confluence it enters Bighorn Lake, where it is joined by the

Shoshone River The Shoshone River is a long river in northern Wyoming in the United States. Its headwaters are in the Absaroka Range in Shoshone National Forest. It ends when it runs into the Big Horn River near Lovell, Wyoming. Cities it runs near or thr ...

. North of the confluence with the Shoshone, the reservoir narrows as the river enters the Bighorn Canyon, where it crosses into

. At the end of the canyon, the river passes through Yellowtail Dam and Afterbay Dam. The river turns to the northeast and enters the Great Plains. At Hardin the river is joined by the Little Bighorn River. Approximately downriver from the Little Bighorn, in Big Horn County, the Bighorn empties into the

Names

The Bighorn River has also been known as the Great Horn River, Le Corne and ''Iisaxpúatahcheeaashisee'' in the Apsáalooke language which translates to English as ''Large Bighorn Sheep River''. Its

Gros Ventre The Gros Ventre ( , ; meaning "big belly"), also known as the Aaniiih, A'aninin, Haaninin, Atsina, and White Clay, are a historically Algonquian-speaking Native American tribe located in north central Montana. Today the Gros Ventre people are ...

name is ats, ʔɔ́tééíníícááh, lit=wild sheep river, label=none.

Notes

External links

State of Wyoming: Bighorn River Basin

Wyoming Game and Fish map showing the Wind River becoming the Bighornarchive
{{authority control Rivers of Montana Rivers of Wyoming Rivers of Yellowstone County, Montana Rivers of Treasure County, Montana Rivers of Big Horn County, Montana Rivers of Carbon County, Montana Tributaries of the Yellowstone River Rivers of Big Horn County, Wyoming Rivers of Washakie County, Wyoming

Course

Names

See also

Further reading

Notes

External links