The Bighorn Basin is a

plateau In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides ...

region and

intermontane Intermontane is a physiographic adjective formed from the prefix " inter-" (''signifying among, between, amid, during, within, mutual, reciprocal'') and the adjective "montane" (inhabiting, or growing in mountainous regions, especially cool, moi ...

basin, approximately 100 miles (160 km) wide, in north-central

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 ...

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., ...

. It is bounded by the

Absaroka Range The Absaroka Range ( or ) is a sub-range of the Rocky Mountains in the United States. The range stretches about across the Montana– Wyoming border, and at its widest, forming the eastern boundary of Yellowstone National Park along Paradise ...

on the west, the

Pryor Mountains The Pryor Mountains are a mountain range in Carbon and Big Horn counties of Montana, and Big Horn County, Wyoming. They are located on the Crow Indian Reservation and the Custer National Forest, and portions of them are on private land. The ...

on the north, 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 ...

on the east, and 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 b ...

and Bridger Mountains on the south. It is drained to the north by tributaries of the

Bighorn River The Bighorn River is a tributary of the Yellowstone, approximately long, in the states of Wyoming and Montana in the western United States. The river was named in 1805 by fur trader François Larocque for the bighorn sheep he saw along its ba ...

, which enters the basin from the south, through a gap between the Owl Creek and Bridger Mountains, as the Wind River, and becomes the Bighorn as it enters the basin. The region is semi-arid, receiving only 6–10 in (15–25 cm) of rain annually. The largest cities in the basin include the Wyoming towns of

Cody Cody may refer to: People *Cody (given name) *Cody (surname) * Cody (wrestler), a ring name of Cody Runnels Places Canada *Cody, British Columbia United States * Cody, Florida * Cody (Duluth), Minnesota * Cody, Missouri * Cody, Nebraska *Cody, ...

Thermopolis Thermopolis is the county seat and largest town in Hot Springs County, Wyoming, United States. As of the 2020 U.S. Census, the town population was 2,725. Thermopolis is Greek for "hot city." It is home to numerous natural hot springs, in whi ...

, Worland, and Powell.

Sugar beet A sugar beet is a plant whose root contains a high concentration of sucrose and which is grown commercially for sugar production. In plant breeding, it is known as the Altissima cultivar group of the common beet ('' Beta vulgaris''). Together ...

s, pinto beans, sunflowers, barley, oats, corn and alfalfa hay are grown on irrigated farms in the region.

History

The basin was explored by

John Colter John Colter (c.1770–1775 – May 7, 1812 or November 22, 1813) was a member of the Lewis and Clark Expedition (1804–1806). Though party to one of the more famous expeditions in history, Colter is best remembered for explorations he made ...

in 1807. Just west of Cody, he discovered geothermal features that were later popularly called "

Colter's Hell Colter's Hell is an area of fumaroles and hot springs on the Shoshone River near Cody in the U.S. state of Wyoming. The thermal area covers about at the mouth of the Shoshone's canyon. Its thermal activity has declined since its description by ...

". The region was later transversed by the Bridger Trail, which was blazed in 1864 by

Jim Bridger James Felix "Jim" Bridger (March 17, 1804 – July 17, 1881) was an American mountain man, trapper, Army scout, and wilderness guide who explored and trapped in the Western United States in the first half of the 19th century. He was known as Old ...

to connect the

Oregon Trail The Oregon Trail was a east–west, large-wheeled wagon route and emigrant trail in the United States that connected the Missouri River to valleys in Oregon. The eastern part of the Oregon Trail spanned part of what is now the state of Kans ...

to the south with

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 ...

. The route was an important alternative to the

Bozeman Trail The Bozeman Trail was an overland route in the western United States, connecting the gold rush territory of southern Montana to the Oregon Trail in eastern Wyoming. Its most important period was from 1863–68. Despite the fact that the maj ...

, which had crossed 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 ...

, but had been closed to white settlers following

Red Cloud's War Red Cloud's War (also referred to as the Bozeman War or the Powder River War) was an armed conflict between an alliance of the Lakota, Northern Cheyenne, and Northern Arapaho peoples against the United States that took place in the Wyoming and M ...

. Around the turn of the 20th century the Bighorn Basin was settled by ranchers such as William "Buffalo Bill" Cody who founded the town of Cody and owned a great deal of land surrounding 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 ...

. The

Chicago, Burlington and Quincy Railroad The Chicago, Burlington and Quincy Railroad was a railroad that operated in the Midwestern United States. Commonly referred to as the Burlington Route, the Burlington, or as the Q, it operated extensive trackage in the states of Colorado, Illin ...

extended a branch line to Cody in 1901 and ultimately built through the entire basin. In 1904, Cody helped to form the

Shoshone project The Shoshone Project is an irrigation project in the U.S. state of Wyoming. The project provides irrigation for approximately of crops in the Big Horn Basin, fulfilling the vision of local resident and developer Buffalo Bill Cody, who hoped to m ...

, the nation's first federal water development project to help irrigate the western portion of the basin. The project culminated in the construction of the

Buffalo Bill Dam Buffalo Bill Dam is a concrete arch-gravity dam on the Shoshone River in the U.S. state of Wyoming. It is named after the famous Wild West figure William "Buffalo Bill" Cody, who founded the nearby town of Cody and owned much of the land now ...

and reservoir. The wealth in the region also attracted outlaws.

Butch Cassidy Robert LeRoy Parker (April 13, 1866 – November 7, 1908), better known as Butch Cassidy, was an American train and bank robber and the leader of a gang of criminal outlaws known as the " Wild Bunch" in the Old West. Parker engaged in crimin ...

lived near Meeteetse for a while and was arrested at the insistence of local cattle baron Otto Franc and sent to the

Wyoming State Penitentiary The Wyoming State Penitentiary is a historic and current prison in Rawlins, Carbon County, Wyoming, which has operated from 1901. It moved within Rawlins to a new location in 1981. In 2018, it is a Wyoming Department of Corrections state maximu ...

for horse theft. Following his release, he formed the

Wild Bunch The Wild Bunch, also known as the Doolin–Dalton Gang, or the Oklahombres, were a gang of American outlaws based in the Indian Territory in the late 19th and early 20th centuries. They were active in Kansas, Missouri, Arkansas, and Oklahoma Terr ...

gang which operated from the

Hole-in-the-Wall Hole in the Wall may refer to: Colloquial use *In American English, an inconspicuous or unpretentious restaurant or retailer. *In British English, an automated teller machine. *''The Hole In The Wall'', a popular name for a public house. Plac ...

area southeast of the Bighorn Basin. In 1942 one of the nation's ten

Japanese American are Americans of Japanese ancestry. Japanese Americans were among the three largest Asian American ethnic communities during the 20th century; but, according to the 2000 census, they have declined in number to constitute the sixth largest Asi ...

internment camps was located in Park County in the western part of the basin. The camp was named

Heart Mountain Relocation Center The Heart Mountain War Relocation Center, named after nearby Heart Mountain and located midway between the northwest Wyoming towns of Cody and Powell, was one of ten concentration camps used for the internment of Japanese Americans evicte ...

, after nearby Heart Mountain. The camp operated until 1945, and at its peak detained over 10,000 internees.

Geology

The Bighorn Basin forms a geologic

structural basin A structural basin is a large-scale structural formation of rock strata formed by tectonic warping of previously flat-lying strata. They are geological depressions, the inverse of domes. Elongated structural basins are also known as syncline ...

filled with more than of sedimentary rocks from

Cambrian The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago ...

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

in age. Since the early 20th century the basin has been a significant source of petroleum, and has produced more than of oil. The principal reservoir of oil is the Pennsylvanian Tensleep Formation; Other important petroleum horizons are the Mississippian Madison Limestone, Permian Phosphoria Formation and the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

Frontier Sandstone. Some

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...

has been mined in the northern part of the basin, along the

. The eastern section of the basin is famously rich in

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

, with formations such as the Cretaceous period

Cloverly Formation The Cloverly Formation is a geological formation of Early and Late Cretaceous age (Valanginian to Cenomanian stage) that is present in parts of Montana, Wyoming, Colorado and Utah in the western United States. It was named for a post office on th ...

yielding numerous dinosaur fossils. The alluvial strata of the Willwood and Fort Union Formations of the Bighorn Basin contain a well-documented record of the Paleocene-Eocene Thermal Maximum (PETM). Analysis of

paleosol In the geosciences, paleosol (''palaeosol'' in Great Britain and Australia) is an ancient soil that formed in the past. The precise definition of the term in geology and paleontology is slightly different from its use in soil science. In geolo ...

s here shows that the Bighorn Basin became more arid during the PETM, with wet/dry cycles superimposed over this general increase in aridity. These changes in environment are coupled with changes in paleoecology.

Communities

Notable Features

* Red Gulch Dinosaur Tracksite *

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 ...

References

{{Authority control Plateaus of the United States Geology of Wyoming Sedimentary basins of North America Landforms of Big Horn County, Wyoming Landforms of Park County, Wyoming Landforms of Hot Springs County, Wyoming Landforms of Washakie County, Wyoming

History

Geology

Communities

Notable Features

See also

References