Major Deserts of the World

Great Basin Desert

The Great Basin is a large, arid region of the western United States. Its boundaries depend on how it is defined. Its most common definition is the contiguous watershed, roughly between the Rocky Mountains and the Sierra Nevada, that has no natural outlet to the sea. The Great Basin Desert is defined by the extent of characteristic plant species, and covers a somewhat different (and smaller) area. The Great Basin Culture Area, home to several Shoshonean Great Basin tribes, extends further to the north and east than the hydrographic basin. The Basin and Range Province is a geologic region that is most recognizable in the Great Basin but extends well into the Sonoran and Mojave Deserts.

Geology
The Great Basin is considered by geologists to be in the process of stretching and cracking. Although elevated, the crust here is actually relatively thin, and getting thinner. Some geologists speculate that the East Pacific Rise rift zone may be destined in the distant future to split the Great Basin, possibly by way of the Imperial Valley, letting the sea in from the Gulf of California.

Flora and fauna
The Great Basin is predominantly high altitude desert, with the lowest basins just below 4,000 feet and several peaks over 12,000 feet. Most areas are dominated by shrubs, mostly of the Atriplex genus at the lowest elevations and sagebrush at higher elevations. Open woodlands consisting of Utah Juniper, Single-leaf Pinyon (mostly southern areas) or Curl-leaf Mountain Mahogany (mostly northern areas) form on the slopes of most ranges. Stands of Limber Pine and Great Basin Bristlecone Pine can be found in some of the higher ranges. Cottonwoods and Quaking Aspen groves exist in areas with dependable water.