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Bighorn Canyon

National Recreation Area

Montana & Wyoming

cover of park brochure

park geology subheading
Photo of lakeshore at Bighorn Canyon NRA
Bighorn Canyon National Recreation Area, Montana & Wyoming

At first glance, time seems to have stopped at Bighorn Canyon. The lake and the steep-sided canyons provide a peaceful setting for those seeking a break from the daily routine. The focus of the area is 113-kilometer-long (71-mile) Bighorn Lake, created by Yellowtail Dam near Fort Smith, Montana. Dedicated in 1968, the dam provides electric power, water for irrigation, flood control, and recreation. Boating, fishing, waterskiing, swimming, and sightseeing are the principal attractions.

While you enjoy the play of light and shadow on rock and water, take time to contemplate the changes that the land and the life upon it have undergone. Time and water provide the keys to Bighorn Canyon where the land has been shaped by moving water since vast upheavals of the earth's crust produced the Pryor and Bighorn Mountains millions of years ago.

For 22 kilometers (15 miles) upstream from the dam, the lake bisects a massive, arching anticline, exposing fossils that tell of successive times

  • when this land was submerged under a shallow sea,

  • when it was a tropical marsh, and

  • when its conifer forests were inhabited by dinosaurs.
Man first arrived here more than 10,000 years ago, living nomadically as a hunter and gatherer. In modern times, he has further shaped and altered the land.

Most of Bighorn's visitors come to enjoy the recreational opportunities the setting offers. Boaters, water skiers, fishermen, and scuba and skin divers each find special attractions here. But the park holds much to interest the visitor beyond the lake, from spring and summer wildflowers to more than 200 species of birds, and from the stories of life forms adapting to a harsh environment to the modern search for energy. You may obtain more information on what the park offers at visitor centers near Lovell, Wyoming, and between Yellowtail Dam and Fort Smith, Montana. Most of all, we hope you will find your own place of solitude to relax and to enjoy the diversity and timelessness of this uncommon canyon water land.

A Challenging Land
Rivers have always been man's highways. For more than 40,000 years in the New World, men have traveled and made their livings along rivers and streams. But the Bighorn River was too treacherous and too steep-walled until the dam tamed it, so for thousands of years men lived near the river but avoided navigating it.

In a similar way, the broken land here has challenged man's ingenuity, forcing him to devise advantageous strategies of survival. More than 10,000 years ago, ancient Indian hunters drove herds of game into land traps. These Indians lived simply, gathering wild roots and seeds to balance and supplement their meat diet. They made clothes of skirt baskets and sandals of plant fibers, and tools of stone, bone, and wood. The many caves of the Bighorn area provided seasonal shelters and storage areas for these ancient men, as well as for early traders and trappers.

Absaroke means "People of the large-beaked bird", in the Siouan language of the Crow. Their reservation surrounds most of Bighorn Canyon. Originally a farming people, the Crow split off from the Hidatsa tribe more than 200 years ago. They became a renowned hunting people, described by a member of the Lewis and Clark Expedition as "the finest horsemen in the world". In the early 1900s they built an irrigation system at the mouth of the canyon, responding in their own way to the challenge of the land.

Explorers, trappers, and traders found their way up the Bighorn early in the 19th century.

  • The earliest was Charles Larocque who met the Crow at the mouth of the Bighorn in 1805;

  • Captain William Clark passed through a year later.

  • Jim Bridger claimed he had floated through the canyon on a raft, but later fur traders packed their goods overland on the Bad Pass Trail, avoiding the rivers dangers.

During the Civil War the Bozeman Trail led to the mines of western Montana by crossing the Bighorn north of the dam. Open from 1864 to 1868, the trail was bitterly opposed by the Sioux and Cheyenne, though the Crow remained neutral. The Federal Government was forced to close the trail in 1868 after the treaty of Fort Laramie. Fort C.F. Smith, now on private land, guarded the trail as its northernmost outpost. A simple stone monument now commemorates the Hayfield Fight, a desperate but successful defense against marauding Sioux and Cheyenne warriors. in this skirmish a small party of soldiers and civilian haycutters, working 5 kilometers (3 miles) north of Fort C.F. Smith, fought for eight hours until rescued by troops from the fort on August 1,1867.

After the Civil War cattle ranching became a way of life here. Among the huge open-range cattle ranches was the Mason-Lovell (the ML), some of whose buildings remain. Dude ranching, reflected in the remains of Hillsboro, enjoyed a period of popularity at the turn of the century.

The Crow made the transition from hunter-gatherers to ranchers in one generation. They completed an irrigation system in 1904 after twelve years of labor and opened 14,140 hectares (35,000 acres) of land to irrigated farming. Water was diverted into the Bighorn Canal by a 129-meter (416-foot) diversion dam, moving 21 cubic meters (720 cubic feet) of water per second. Visit the Bighorn Canal Headgate, near Afterbay Campground, and other vestiges of the human past.

park maps subheading

The General park map handed out at the visitor center is available on the park's map webpage.

View the park's map to create your own personal maps and images right here.

For information about topographic maps, geologic maps, and geologic data sets, please see the geologic maps page.

photo album subheading

A geology photo album for this park can be found here.

For information on other photo collections featuring National Park geology, please see the Image Sources page.

books, videos, cds subheading

Currently, we do not have a listing for a park-specific geoscience book. The park's geology may be described in regional or state geology texts.

Please visit the Geology Books and Media webpage for additional sources such as text books, theme books, CD ROMs, and technical reports.

Parks and Plates: The Geology of Our National Parks, Monuments & Seashores.
Lillie, Robert J., 2005.
W.W. Norton and Company.
ISBN 0-393-92407-6
9" x 10.75", paperback, 550 pages, full color throughout

The spectacular geology in our national parks provides the answers to many questions about the Earth. The answers can be appreciated through plate tectonics, an exciting way to understand the ongoing natural processes that sculpt our landscape. Parks and Plates is a visual and scientific voyage of discovery!

Ordering from your National Park Cooperative Associations' bookstores helps to support programs in the parks. Please visit the bookstore locator for park books and much more.

geologic research subheading


For information about permits that are required for conducting geologic research activities in National Parks, see the Permits Information page.

The NPS maintains a searchable data base of research needs that have been identified by parks.

A bibliography of geologic references is being prepared for each park through the Geologic Resources Evaluation Program (GRE). Please see the GRE website for more information and contacts.

selected links subheading

NPS Geology and Soils Partners

NRCS logoAssociation of American State Geologists
NRCS logoGeological Society of America
NRCS logoNatural Resource Conservation Service - Soils
USGS logo U.S. Geological Survey

teacher feature subheading

Currently, we do not have a listing for any park-specific geology education programs or activities.

For resources and information on teaching geology using National Park examples, see the Students & Teachers pages.
updated on 01/04/2005  I   http://www.nature.nps.gov/Geology/parks/bica/index.cfm   I  Email: Webmaster
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