Great Basin

Great Basin
watershed
Nearly the size of Texas, the Great Basin is enclosed by the Pacific watershed.
Countries	United States, Mexico
Highest point	Mount Whitney summit
- location	Sierra Nevada Mountains
- elevation	14,505 ft (4,421.1 m)
- coordinates
Lowest point	Badwater Basin (-282 ft)
- location	Death Valley National Park
- coordinates
Area	206,164 sq mi (533,962.3 km²) (see Navbox)
- persistent water (average area)	4,079 sq mi (10,564.6 km²) (see Navbox)
Population	3,163,941 (see Navbox)
Orogeny	Basin and Range Province fault history

The Great Basin is the largest area of contiguous endorheic watersheds of North America and is noted for its arid conditions and Basin and Range topography that varies from the North American lowpoint at Badwater Basin to—less than 100 miles away—the contiguous United States highpoint at the Mount Whitney summit. The watershed spans several physiographic divisions, biomes/ecoregions, deserts, and metropolitan areas and, in addition to being the ancestral homeland of the Great Basin tribes, was the 1849 location of the provisional State of Deseret.

Volcano in the Black Rock Desert Volcanic Field of Utah

Wah Wah Valley, Utah, thunderstorm

Geography

The Great Basin includes valleys, basins, lakes, and mountain ranges^[1] of Basin and Range topography. The Great Basin almost entirely contains the smaller Great Basin physiographic section, which extends into ~10,000 sq mi (26,000 km²) of the Colorado River watershed (including the Las Vegas metropolitan area and northwest corner of Arizona). In addition to the Pacific Ocean, geographic features near the Great Basin include the Continental Divide of the Americas (~65 mi), the Great Divide Basin (~75 mi), and the Gulf of California.

Hydrology

The Great Basin Divide demarcates the Great Basin from the Pacific Ocean, and the southernmost portion of the Great Basin is the watershed area of the Laguna Salada (Mexico). The Great Basin's longest river is the Bear River of 350 mi (560 km),^[2] and the largest river watershed is the Humboldt River drainage of 17,000 sq mi (44,000 km²). Most Great Basin precipitation is snow, and some of the snowmelt and rain "that does not evaporate sinks into the ground to become ground water aquifers", while evaporation of collected water is from geographic sinks.^[3] Lake Tahoe, North America's largest alpine lake, is part of the Great Basin's central Lahontan subregion.^[4] The Great Basin also has several deserts, including the Black Rock Desert (northwest), the Great Salt Lake Desert (NE), the Sevier Desert (E), and the Smoke Creek Desert (NE); as well as large parts of the Great Basin Desert (central), the Mojave Desert (S), and the southernmost Great Basin area in the Sonoran Desert of Baja California.

The Tule Valley watershed and the House Range (Notch Peak) are part of the Great Basin's Great Salt Lake hydrologic unit

Subregions

The Great Basin includes 11 entire hydrologic subregions designated by the United States Geological Survey, as well as 2 contiguous endorheic watersheds that rarely overflow beyond the Great Basin Divide to Pacific Ocean watersheds. In the southwest during an "extremely large rainfall event", the endorheic San Jacinto River watershed floods over the 1256 ft Lake Elsinore sill through the Temescal Wash into the Santa Ana River watershed. Similarly in the northwest, the endorheic Goose Lake (Oregon-California) watershed can overflow into the watershed of the Pit River, which crosses the Cascade Range. Additionally, a small portion of water from the Great Basin drains into the 92 miles of canals on the 242 mile Colorado River Aqueduct and is pumped outside of the Great Basin.^[5] Conversely, several canals provide Great Basin inflow/outflow, e.g., the All-American Canal flows to the endorheic Salton Sink and the Los Angeles Aqueduct flows out of the Mojave (a 1905 Colorado River overflow flooded to the Salton Sea). Finally, the Tulare Lake- no longer has occasional overflow northward into the San Joaquin River subregion. The Long Valley Caldera volcanic region is located within the North Mojave-Mono Lake subregion of the Great Basin.

Wheeler Peak, one of the tallest peaks within the Great Basin

Biogeography

Although mostly within the North American Desert ecoregion, portions of the Great Basin extend into the Forested Mountain and Mediterranean California ecoregions. The semi-arid areas of the Forested Mountain ecoregion include the White Mountains and Inyo Mountains. Extending north of the 42nd parallel north, the Northern Basin and Range (ecoregion) has its southern border at the highest shoreline of the Pleistocene Lake Bonneville. The south edge of the Central Basin and Range ecoregion is in Nevada, north of the south edge of the Great Basin section.

Fauna

Great Basin wildlife includes Pronghorn, Mule Deer, Mountain Lion and Lagomorphs such as Black-tailed Jackrabbit and Desert Cottontail and the coyotes that prey on them. Ground squirrels are common, but they generally venture above ground in only the spring and early summer. Packrats, Kangaroo rats and other small rodents are also common, but these are predominantly nocturnal. Elk and Bighorn Sheep are present but uncommon. Small lizards such as the Great Basin fence lizard, Longnose Leopard Lizard and Horned Lizard are common, especially in lower elevations. Rattlesnakes and Gopher snakes are also present. The Inyo Mountains Salamander is endangered. Shorebirds such as Phalaropes and Curlews can be found in wet areas. American White Pelicans are common at Pyramid Lake. Golden Eagles are perhaps more common in the Great Basin than anywhere else in the US. Mourning Dove, Western Meadowlark, Black-billed Magpie and Common Raven are other common bird species.

Two endangered species of fish are found in Pyramid Lake that lies in the Great Basin: the Cui-ui sucker fish and the Lahontan cutthroat trout.^[6]

Large invertebrates include tarantulas (Aphonopelma genus) and Mormon crickets. Exotic species include: Chukar, Grey Partridge and Himalayan Snowcock have been successfully introduced to the Great Basin, although the latter has only thrived in the Ruby Mountains. Cheatgrass, an Invasive species which was unintentionally introduced, forms a critical portion of their diets. Feral horses (Mustangs) and wild burros are other highly reproductive, and ecosystem controversial, alien species. Most of the Great Basin is open range and domestic cattle and sheep are widespread, altering the bioregions.

Flora

Utah Juniper/Single-leaf Pinyon (southern regions) and Mountain Mahogany (northern regions) form open Pinyon-juniper woodland on the slopes of most ranges. Stands of Limber Pine and Great Basin Bristlecone Pine (Pinus longaeva) can be found in some of the higher ranges (the Methuselah tree is the nearly 5000 years old). In riparian areas with dependable water cottonwoods (Populus fremontii) and Quaking Aspen (Populus tremuloides) groves exist. Grasslands contain the native Great Basin wildrye.

Political geography

The Great Basin's most populous city is Reno, Nevada, on the western side (217,016); and routes across the basin include Interstate 80 (through Reno and Salt Lake City), Interstate 15, and Interstate 70 in Utah. Railroad transportation routes also pass through Reno and Salt Lake City.

History

Sediment build-up over thousands of years between undersea ranges created relatively flat lacustrine plains in underwater portions of the prehistoric area that would be named the Great Basin after they drained.^[7] For example, after forming ~32,000 years ago, Lake Bonneville overflowed ~14,500 years ago in the Bonneville Flood through Red Rock Pass and lowered to the "Provo Lake"^[8] level (the Great Salt Lake, Utah Lake, Sevier Lake, Rush Lake, and Little Salt Lake remain).^[9] Lake Lahontan, Lake Manly, and Lake Mojave were similar Pleistocene seas.

Paleo-Indian habitation by the Great Basin tribes began as early as 10,000 B.C. (the Numic-speaking Shoshonean peoples arrived as late as 1000 A.D.).^[10] Archaeological evidence of habitation sites along the shore of Lake Lahontan date from the end of the ice age when its shoreline was approximately 500 ft (150 m) higher along the sides of the surrounding mountains.

The 1860-61 Pony Express stations in the Great Basin extended between west of Lake Tahoe and northeast of the Great Salt Lake.

Exploration of the Great Basin occurred during the 18th century Spanish colonization of the Americas, and Benjamin Bonneville explored the northeast portion during an 1832 expedition. The United States had acquired control of the area north of the 42nd parallel via the 1819 Adams–Onís Treaty (Spain) and 1846 Oregon Treaty (United Kingdom), which were followed by complete control via the 1848 Mexican Cession. The first Euro-American settlements were connected with the eastern regions of the 1848 California Gold Rush, with its immigrants crossing the Great Basin on the California Trail along Nevada's Humboldt River to Carson Pass in the Sierras. The first American religious settlement effort was the Mormon provisional State of Deseret in 1849 in present day Utah and northern Nevada. The Oregon Territory was established in 1848 and the Utah Territory in 1850.

In 1869 the First Transcontinental Railroad was completed at Promontory Summit in the Great Basin. Circa 1902, the San Pedro, Los Angeles and Salt Lake Railroad was constructed in the lower basin and Mojave Desert for California-Nevada rail service to Las Vegas, Nevada.

To close a 1951 Indian Claims Commission case, the Western Shoshone Claims Distribution Act of 2004 established the United States payment of $117 million to the Great Basin tribe for the acquisition of 39,000 square miles (100,000 km²).^[11] The Dixie Valley, Nevada, earthquake (6.6-7.1) in the Great Basin was in 1954. The Mojave and Colorado Deserts Biosphere Reserve (4 conserved areas) was designated in 1984, and in 1986 and 1994, the Great Basin National Park and the Mojave National Preserve were established. In 2009, the American Land Conservancy's Great Basin Program reserved the Green Gulch mule deer migration corridor as part of "over 80,000 acres [conserved] in Nevada and the Eastern Sierras".^[12]

External media
Images
	USGS: North America Basins Map
	Great Basin Map
Videos
	Great Basin Shrub Steppe (modem version)
	Exploring the Great Basin (modem version)

References

1. ↑ "Basin and Range Province". Geologic Provinces of the United States. United States Geological Survey. 2004. http://geomaps.wr.usgs.gov/parks/province/basinrange.html. Retrieved 2009-01-10. 
2. ↑ ^{2.0 2.1} "Bear River Watershed Description". Bear River Watershed Information System. http://www.bearriverinfo.org/description/. Retrieved 2010-04-28.  (an additioanl ~1% is in the SW corner of WY)
3. ↑ "Great Basin". Geologic Provinces of the United States: Basin and Range Province. nature.nps.gov: National Park Service. http://www.nature.nps.gov/Geology/usgsnps/province/brgrbas.html. Retrieved 2009-01-10. 
4. ↑ "Amazing Lake Tahoe". Lake Tahoe Visitors Authority. http://www.bluelaketahoe.com/page.php?p=amaz&l=1. Retrieved 2008-10-26. 
5. ↑ "Colorado River Aqueduct". Center for Land Use Interpretation. http://ludb.clui.org/ex/i/CA3318/. Retrieved 2010-04-23. 
6. ↑ Hogan, C.Michael; Papineau, Marc, et al (1987). Development of a dynamic water quality simulation model for the Truckee River. Environmental Protection Agency Technology Series. Washington D.C.: Earth Metrics Inc.. 
7. ↑ Jackson, Richard H.; Stevens, Dale J. (1981). "Physical and Cultural Environment of Utah Lake and Adjacent Areas". Great Basin Naturalist Memoirs (5: Utah Lake Monograph): 5. https://ojs.lib.byu.edu/ojs/index.php/gbnmem/article/view/2941/3289. Retrieved 2010-04-06. 
8. ↑ Gilbert, Grove Karl (1890) (Google Books). Lake Bonneville. p. 127. http://books.google.com/books?id=NY0sAAAAYAAJ&pg=RA1-PA127. Retrieved 2010-04-23. 
9. ↑ Morgan, Dale L (1947). The Great Salt Lake. Salt Lake City: University of Utah Press. p. 22. ISBN 0-87480-478-7. 
10. ↑ "Archaeology, Cultural Transmission, and the Indigenous Native American Indians of the Great Basin Region of North America". Bauu Institute. http://www.bauuinstitute.com/Articles/ArchaeologyCultureGreatBasin.html. Retrieved 2010-04-22. 
11. ↑ "Action Alert!". Shundahai Network. http://www.shundahai.org/claims_action_alert_0501.htm. Retrieved 2010-04-22. 
12. ↑ "Great Basin". Programs. American Land Conservancy. http://www.alcnet.org/projects/overview/basin. Retrieved 2010-01-11. 

	Columbia Basin, Klamath	Columbia (Snake)	Colorado (Green)
	central California coastal subregion		Colorado River
		watersheds adjacent to the Great Basin
	southern California coastal subregion	Colorado (Baja area)	Colorado River