Powder River is a tributary of the

Yellowstone River The Yellowstone River is a tributary of the Missouri River, approximately long, in the Western United States. Considered the principal tributary of upper Missouri, via its own tributaries it drains an area with headwaters across the mountains a ...

, approximately long in northeastern

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 t ...

and southeastern

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

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

. Combined with its tributary, the South Fork Powder River, it is 550 miles long. It drains an

area Area is the quantity that expresses the extent of a region on the plane or on a curved surface. The area of a plane region or ''plane area'' refers to the area of a shape or planar lamina, while '' surface area'' refers to the area of an op ...

historically known as the

Powder River Country The Powder River Country is the Powder River Basin area of the Great Plains in northeastern Wyoming, United States. The area is loosely defined as that between the Bighorn Mountains and the Black Hills, in the upper drainage areas of the Powd ...

on the

high plains High Plains refers to one of two distinct land regions: * High Plains (United States), land region of the western Great Plains *High Plains (Australia) The High Plains of south-eastern Australia are a sub-region, or more strictly a string of adja ...

east 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 ...

. It rises in three forks in north central Wyoming. The North and Middle forks rise along the eastern slope of the Bighorn Mountains. The South Fork rises on the southern slopes of the Bighorn Mountains west of

Casper Casper may refer to: People * Casper (given name) * Casper (surname) * Casper (Maya ruler) (422–487?), ruler of the Mayan city of Palenque * Tok Casper, first known king of Maya city-state Quiriguá in Guatemala, ruling beginning in 426 * Da ...

. The three forks meet on the foothills east of the Bighorns near the town of Kaycee. The combined stream flows northward, east of the Bighorns, and into Montana. It is joined by the Little Powder near the town of Broadus, and joins the Yellowstone approximately downriver from Miles City, Montana. The Powder River was so named (in the English language as well as in local indigenous languages) because the sand along a portion of its banks resembles powder or dust.

Notes

{{Authority control Rivers of Montana Rivers of Wyoming Bodies of water of Prairie County, Montana Bodies of water of Custer County, Montana Tributaries of the Yellowstone River Bodies of water of Johnson County, Wyoming

See also

Notes