Bighorn Basin

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The Bighorn Basin in Wyoming
The Bighorn Basin in Wyoming

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 Bighorn Mountains on the east, and the Owl Creek Mountains and Bridger Mountains on the south. It is drained to the north by tributaries of the Bighorn River, 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 basin was explored by John Colter in 1807. It was later transversed by the Bridger Trail, which was blazed in 1864 by Jim Bridger to connect the Oregon Trail to the south with Montana. The route was important alternative to the Bozeman Trail, which had crossed the Powder River Country, but had been closed to white settlers following Red Cloud's War.

The largest cities in the basin include the Wyoming towns of Thermopolis, Worland, and Powell. Sugar beets are grown on irrigated farms in the region.

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[edit] Geology

The Bighorn Basin forms a geologic structural basin filled with more than 20,000 feet of sedimentary rocks from Cambrian to Miocene in age. Since the early 20th century the basin has been a significant source of petroleum, and has produced more than 1.4 billion barrels of oil. The principal souce of oil is the Pennsylvanian Tensleep Formation; Other important petroleum horizons are the Mississippian Madison Limestone and the Cretaceous Frontier Sandstone.[1] Some uranium has been mined in the northern part of the basin, along the Bighorn Mountains (see Uranium mining in Wyoming).

[edit] Communities



[edit] Notable Features

[edit] References

  1. ^ John P. Weldon (1972) The Big Horn Basin in Geologic Atlas of the Rocky Mountain Region, Denver: Rocky Mountain Association of Geologists, p.270-272.