Great Salt Lake Information System

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Map of the Great Salt Lake Basin
19,261 km2 / 7,437 mi2

Minimum:  1,280 m / 4,198 ft
Maximum:  3,863 m / 12,673 ft
Range:  2,583 m / 8,475 ft

Minimum:  229 mm / 9 in
Maximum:  1,549 mm / 61 in
Average:  533 mm / 21 in

Bear River Watershed

The Bear River Basin, located in northeastern Utah, southeastern Idaho and southwestern Wyoming, comprises 7,500 square miles of mountain and valley lands including 2,700 in Idaho, 3,300 in Utah and 1,500 in Wyoming. The Bear River crosses state boundaries five times and is the largest stream in the western hemisphere that does not empty into the ocean. It ranges in elevation from over 13,000 to 4,211 feet and is unique in that it is entirely enclosed by mountains, thus forming a huge basin with no external drainage outlets. The Bear River is the largest tributary to the Great Salt Lake.

Throughout the basin, agricultural lands, both developed and undeveloped, as well as the urban areas are located in the valleys along the main stem of the river and its tributaries. In addition to these private lands, the Bear River watershed includes vast amounts of federal (both Bureau of Land Management and Forest Service) and state lands that serve a range of natural and agricultural functions, each of which generates its unique impacts and demands on water resources.

The Bear River begins its 500 mile course at well above 12,000 feet in the alpine, conifer and aspen forest of northeastern Utah's Uinta Mountains. Its headwaters, fueled by several hundred inches of yearly snowfall, flows northward into southwestern Wyoming, back into Utah, again into Wyoming, into southeastern Idaho, diverted by man made canals into and back out of Bear Lake, then eventually makes a huge U-turn southward and back, once again, into Utah and its journey's end, the Great Salt Lake. A trek which earns the Bear River, the principal stem of the Bear River Basin, the distinction of being the largest stream in the western hemisphere not flowing into an ocean. Yet from the river's headwaters to where it empties into the Bear River Bay of the Great Salt Lake, the distance is only about 90 miles in a straight line. In addition, the Bear River and its tributaries represent approximately 60 percent of the 2 million total acre feet of surface inflow water entering the Great Salt Lake, the fourth largest terminal lake in the world.

An indisputable jewel of the Bear River Basin is the natural, sapphire blue, Bear Lake. Often called the Carribean of the Rockies, the regionally important, fresh water Bear Lake, with its 110 square miles of surface area, is of special concern because of numerous distinctive qualities (not to mention a storage potential of 1.42 million acre-feet of water reserves.) Until the early 1900's the lake was completely isolated for some 28,000 years, resulting in a unique water chemistry and the development of four species of fish found nowhere else in the world - second only to Russia's Lake Baikal, the largest fresh water lake on Earth.

During the years of 1908 to 1918, however, the isolation came to an end as a diversion dam, an inlet and outlet canal with a pumping station were constructed allowing the Bear River to flow into and out of the lake. Bear Lake has been regulated ever since for downstream electrical power production and contracted irrigation.

The watershed of the 4.8 million acre Bear River Basin is heavily exploited, as is the energy generated from the inertia of a near 9,000 feet overall drop in elevation. The main stem of the Bear River alone is completely diverted in three reaches, powers six hydroelectric plants, supplies the water for hundreds of irrigation companies and, all the while, provides innumerable opportunities for recreational activities. Over 150 lakes and reservoirs impound precious water reserves within the basin.

The basin's topography, from the rugged peaks of the High Uintas Wilderness Area to lowland marshes girding the Bear River Migratory Bird Refuge, is richly diverse. Vegetation in the basin is divided into about 27 percent aspen and conifer forest, 37 percent juniper, sagebrush and other brush varieties, and 20 percent dedicated to cropland. Precipitation amounts vary dramatically within the basin. Up to 40 inches - mostly as snowfall - accumulates in the higher alpine forest areas, contrasting with the 9 inches or less falling on the semi-arid desert surrounding the Great Salt Lake Basin. An important note, however, is that during the May to September growing season, agricultural areas receive, on average, a mere five to six inches of precipitation compared to crop water requirements of 20 to 30 inches. The difference is made up using irrigation water diverted from the Bear River and its tributaries.


L A N D   C O V E R K M 2 P E R C E N T
Urban 81 0.4
Forest 2,878 15
Rangeland 11,599 60
Agriculture 3,601 19
Other 1,101 6
TOTAL 19,261 100

L A N D   O W N E R S H I P K M 2 P E R C E N T
Bureau of Land Management 2,921 15
Forest Service 4,167 22
State 1,072 6
Private 10,550 55
Other 550 3
TOTAL 19,259 100