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Great Salt Lake

Site Facts

Country, State, Province/Region:

United States of America, Utah

Relative Location:

Within Davis, Box Elder, Tooele, Salt Lake, and Weber Counties


40º - 42º N, 112º - 113º W



Basis for Designation:

Supports 1.4 million shorebirds annually, including a single day count of Wilson’s Phalaropes exceeding 500,000 (>33% of the global population), 250,000 American Avocets (56% of population) and 65,000 Black-necked Stilts (37%)


780,000 hectares (1,927,420 acres)


March 1991

Site Owner/Steward:

State of Utah
Utah Department of Natural Resources
U.S. Fish and Wildlife Service.
The Nature Conservancy and many privately owned duck clubs (above the lake’s meander line)

Site Partners:

Friends of Great Salt Lake
Great Salt Lake Audubon Society
Utah Chapter of The Nature Conservancy
Utah Office of Tourism

Human Population within 100 km:

2.45 million


John Luft
Utah Division of Wildlife Resources


Great Basin Sea
Located in northwestern Utah within the Great Basin of the United States, Great Salt Lake (GSL) is the largest terminal lake in North America. Having no outlet, this saline lake loses water through evaporation and leaves minerals and salts behind. As a relatively shallow lake (7-13 meters deep) with an expansive, low-gradient bottom, it varies widely in area as climatic and consumptive water-use conditions change. Since record keeping began in 1847, GSL elevations have fluctuated 6.2 meters (20.3 feet) in depth. Correspondingly, the lake’s area fluctuated between 246,000 and 621,600 hectares (607,880 - 1,536,010 acres).

Rock-fill transportation causeways divide GSL into four distinct bays, each with its own physical, chemical, and biological properties creating unique aquatic environments. Generally speaking, gradations of salinity among the four bays vary from freshwater areas to areas twice as salty as the ocean, and to areas completely saturated with salt. Fish and most other aquatic organisms cannot survive in the salty areas of the lake. Instead, two invertebrate halophiles, brine shrimp and brine flies, have complete reign in the saltwater ecosystem, providing incredibly abundant food resources for avian use. In the fresher-water bays, corixids (water boatman) and chironomids (midges) are important food sources.

Great Salt Lake Landscape
Great Salt Lake lies within a cold desert environment characterized by sparse and low-lying drought and salt-tolerant plants. Surrounding the lake’s rocky shorelines, playas, salt marshes, and extensive mudflats, is over 162,000 hectares (400,000 acres) of freshwater wetlands - over 75% of Utah’s total.   These natural and constructed habitats consist of deep reservoirs, shallow ponds, wet meadows, flooded agricultural fields, and riparian corridors. 

Wetlands concentrate around river and stream deltas extending along the eastern perimeter of GSL wrapping around the northern and southern shores. Protected wetlands include Bear River Migratory Bird Refuge managed by the U.S. Fish and Wildlife Service; a Bureau of Land Management Wildlife Habitat Area; eleven state Wildlife Management Areas; three state parks; private refuges run by The Nature Conservancy, Audubon, and others; and numerous privately owned duck clubs.

Two main industries utilize the natural resources of GSL. Mineral extraction companies own and lease large portions of the GSL mudflats for evaporation ponds. These companies produce commodities like salt, deicing salts, sulfate of potash fertilizer, and magnesium metal.  Secondly, brine shrimp harvest companies skim cysts from the lake and sell them around the world for use as food in aquacultural production of fish and table shrimp.

Avian Oasis
Peak counts of shorebirds show that over 1.4 million use Great Salt Lake as breeding and staging areas. A single count of Wilson’s Phalaropes during fall migration exceeded 500,000, which is 30% of the global population. As many as 250,000 American Avocets and 65,000 Black-necked Stilts also stage on the shores of GSL. Individually, each of these species qualify GSL as a WHSRN Hemispheric Site, but several other shorebird species spend time at GSL in large numbers: 

Snowy Plover – 5,511
Marbled Godwit – 44,000
Western Sandpiper – 190,000
Long-billed Dowitcher – 59,000
Red-necked Phalarope – 240,000

Information about these and other shorebirds can be found in the Species Conservation Plans.

Twin Sites
Great Salt Lake is part of a "three-way twinning" with Laguna Mar Chiquita (Argentina, Hemispheric) and Mono Lake (California, International) WHSRN Sites in June 1992, based on ecological similarites and large numbers of migrating Wilson's Phalaropes. It is also part of "Linking Communities" initiative with Chaplin Lakes (Canada, Hemispheric) and Marismas Nacionales (Mexico, International) WHSRN Sites.

Ecology & Conservation

Great Salt Lake Waterbird Survey
An intensive waterbird survey from 1997-2001 greatly expanded the information available on avian numbers and use patterns at Great Salt Lake (GSL). Results from the April through September survey show that over the five-year study, mean yearly use-days for shorebirds exceed 26.1 million (a use-day is one bird spending 24 hours within the survey area and survey time frame). For all waterbirds combined, including grebes, pelicans, cormorants, herons, egrets, ibis, waterfowl, rails, cranes, shorebirds, gulls, and terns, there were over 86.7 million bird use-days.

Shorebirds of Great Salt Lake
The Utah Birds Records Committee recognizes 43 shorebird species at Great Salt Lake. Peak lake-wide counts, many coming from the GSL Waterbird Survey, are listed after each of the 22 annually occurring species (B = Local Breeder):

Black-bellied Plover – 3,383
Snowy Plover (B) – 5,511
Semipalmated Plover – 78>
Killdeer (B) – 3,020
Black-necked Stilt (B) – 65,000
American Avocet (B) – 250,000
Spotted sandpiper (B) – 101
Solitary Sandpiper – 3
Greater Yellowlegs – 555
Willet (B) – 2,289
Lesser Yellowlegs – 1,832
Long-billed Curlew (B) – 409
Marbled Godwit – 43,833
Sanderling – 8,477
Western Sandpiper – 194,536
Least Sandpiper – 8,041
Baird’s Sandpiper – 1,130
Pectoral Sandpiper – 15
Long-billed Dowitcher – 58,880
Wilson’s Snipe (B) – 62
Wilson’s Phalarope (B) – 533,000
Red-necked Phalarope – 240,000

Eight rare transient shorebirds include American Golden-Plover, Whimbrel, Ruddy Turnstone, Red Knot, Semipalmated Sandpiper, Dunlin, Stilt Sandpiper, and Short-billed Dowitcher. Also recorded in the area by a few lucky birders are Pacific Golden-Plover, Mountain Plover, Wandering Tattler, Upland Sandpiper, Hudsonian Godwit, Bar-tailed Godwit, White-rumped Sandpiper, Sharp-tailed Sandpiper, Purple Sandpiper, Curlew Sandpiper, Buff-breasted Sandpiper, Ruff, and Red Phalarope.

Other Bird Life
Great Salt Lake is also important to many other bird species. Every fall, one to two million Eared Grebes stage on the lake, fattening and molting while feeding almost solely on the abundant brine shrimp. One of the world's largest populations of White-faced Ibis nest in the emergent marshes of the lake (27,000 breeding adults). Colonies of Franklin’s Gulls often nest with the ibis. 

Several of the islands within the GSL support breeding colonies of American White Pelicans, Double-crested Cormorants, Great Blue Herons, Caspian Terns, and California Gulls. At times, the pelican colony on Gunnison Island, with up to 20,000 breeding adults, ranks as one of the largest in North America. GSL hosts the largest number of breeding California Gulls (160,000), including the world’s largest recorded, single colony. Breeding waterfowl are estimated to exceed 230,000 birds. Common Goldeneye, in numbers over 45,000, winter on the GSL feeding on brine fly larvae when freshwater food sources freeze. Migrating fall Tundra Swans can range from 40,000 to 60,000 birds. Numerous other species depend upon the lake, such as Black-crowned Night Herons, egrets, terns, raptors (including Bald Eagles and Peregrine Falcons), swallows, and songbirds.

Threats to Shorebirds
Many of the threats facing shorebirds are a result of the large and growing metropolitan areas near the Great Salt Lake and within the watershed. Habitat conversion and encroachment near the shores of the lake reduce seasonal playa habitat and upland nesting areas for shorebirds. These buffer areas have the potential to give shorebirds shallow water habitat even when the lake rises again. Without them, available habitat will get pinched between development and the shoreline.

Although the lake bed is a protected state resource, the Great Salt Lake Management Plan gives authority to the Utah Division of Forestry, Fire and State Lands to lease specific areas of the lake. Leases for mineral extraction through the creation of large evaporation ponds cover large portions of the lakebed and there is a current proposal to add 21,000 (52,000 acres) in new pond leases within Gunnison, Gilbert, and Bear River Bays. Not only are low gradient mudflats covered by evaporation ponds in general, when lake waters are high, deep water abuts pond dikes and eliminates shallow water foraging habitat for shorebirds. Related changes in salinity could upset brine shrimp and brine fly productivity, thereby, affecting the food base of millions of birds. Potential oil lease development within the lake is a related concern as possible spills could greatly affect habitat viability over large areas and physically harm birds unfortunate enough to get caught in a spill.

Water quantity and quality concerns at GSL are directly related to the local population and its growth. Reservoirs store mountain runoff for agricultural, industrial, and domestic uses that would normally flow into GSL and surrounding wetlands. Drought conditions increase the demand on reservoirs and reduce the amount of water reaching the lake. These conditions lower lake levels and can leave large expanses of the lake bottom dry and unproductive.

Since GSL has no outlet, all the riverine and atmospheric inputs tend to stay within the lake. Historic and current contamination through industry, mining, urban runoff, and treated sewer discharges lead to increased concentrations of nutrients, heavy metals, and other emerging contaminants like pharmaceuticals, hormones, organic compounds, and detergents. Coordination by the Utah Department of Environmental Quality is developing water quality standards for GSL. A standard for selenium concentrations in GSL was recently completed and includes analyses of potential effects on shorebirds and other wildlife.

Recent research determined that GSL contains some of the highest concentrations of mercury and, the more toxic, methyl mercury ever measured in water. The Utah Department of Health issued consumption advisories for three bird species: Common Goldeneye, Northern Shoveler, and Cinnamon Teal. The accumulation of mercury in the GSL ecosystem and food chain is currently being studied.

The invasive species, common reed (Phragmites australis), grows dense in vast expanses that choke out native plant species, which are more beneficial to shorebirds and other avian species. Labor and cost intensive programs are working to reduce this weed within many protected areas. Non-native predators reduce breeding success of shorebirds, and disease outbreaks of avian botulism in late summer produce high mortalities (1000s) for migrating shorebirds including American Avocets and phalaropes.

Research and Management Activities
The Great Salt Lake Ecosystem Program (GSLEP) within the Utah Division of Wildlife Resources is in charge of monitoring and regulating the brine shrimp harvest every fall to ensure a sustainable harvest year after year. Research activities focus on understanding biotic and abiotic characteristics of the GSL ecosystem and how they relate to a healthy brine shrimp population and cyst harvest. Brine shrimp demographics and density, cyst hatchability, chlorophyll a concentration, salinity, dissolved oxygen are just some of the data gathering activities done on a weekly or bimonthly basis. These data help formulate and refine a predictive model of brine shrimp growth and population estimates. 

Aquatics research is a priority of the GSLEP and some topics are contracted through institutions of higher learning and the U.S. Geological Survey. Recent, current, and possible future topics include optimal brine shrimp habitat requirements, over-winter cyst survival, brine shrimp population genetics, GSL bathymetry, hydrodynamic modeling, contaminant monitoring, and understanding the relationship of parasitic cestodes in brine shrimp and avian hosts.

The GSLEP also researches avian communities throughout the GSL ecosystem due to the explicit relationship between birds and their food (brine shrimp and brine flies). The extensive GSL Waterbird Survey (see heading above) continues today, albeit in a much scaled down version to allow for other bird monitoring efforts. Recent and ongoing research includes participation in a continental-wide survey of breeding Snowy Plovers and a region-wide colonial nesting survey, secretive marsh bird surveys, and annual breeding American White Pelican and staging Eared Grebe surveys.

Ongoing development of a Great Salt Lake Shorebird Conservation Strategy by local biologists, with coordination by the Intermountain West Joint Venture, will incorporate shorebird population objectives and estimates, energy requirements, habitat availability, and food density into a bioenergetics model for GSL. The Strategy will assess current trends and threats, conservation priorities, and strategies while making recommendations on monitoring, research, and management for GSL shorebirds.

Special Information

Great Salt Lake WHSRN Site partners held a dedication ceremony in August 1992.

Birding and Recreational Activities
Each May the Great Salt Lake Bird Festival provides locals and international visitors alike many opportunities to experience the area’s abundant bird life. The festival organizes guided bird tours to local birding hotspots, birding workshops and exhibits and a banquet dinner with a keynote address by a nationally known speaker.

Even casual, every-day observers will find easy access to many protected areas around the lake. Bear River Migratory Bird Refuge, Great Salt Lake Shorelands Preserve, Farmington Bay WMA, and Antelope Island State Park are all excellent places to explore the various habitats and the incredible birds that the Great Salt Lake ecosystem has to offer. Not only will visitors to Antelope Island see lots of birds, they can partake in many other activities including hiking, road and mountain biking, horseback riding, swimming and kayaking in the Great Salt Lake, picnicking, camping, viewing historic and prehistoric museum exhibits, and watching wildlife such as bison, pronghorn, mule deer, coyotes, and bighorn sheep. Popular annual events include a balloon and kite stampede in September and the buffalo roundup in October.

Recreational boaters and sailors can explore the lake from two public marinas. One marina is on the northern tip of Antelope Island State Park and the other is on the southern end of the lake within Great Salt Lake State Park. Freshwater boating and fishing is available at Willard Bay State Park in the north between Brigham City and Ogden. Hunting is also an option at many of the state and federal refuges, as well as privately-owned duck clubs.

Land art connoisseurs shouldn’t pass up the Spiral Jetty by Robert Smithson. During low lake levels the jetty becomes visible off of Rozel Point, unshielded by the pink water of Gunnison Bay. On the way to the jetty is the Golden Spike National Historic Site. This site and museum marks the joining of the first transcontinental railroad on May 10, 1869.


John Luft
Utah Division of Wildlife Resources

Site Partners:

Friends of Great Salt Lake, P.O. Box 2655, Salt Lake City, Utah 84110-2655; (801) 583-5593;

Great Salt Lake Audubon Society, P.O Box 520867, Salt Lake City, Utah 84152-0867; (800) 355-8110;

Utah Chapter of The Nature Conservancy, 559 E. South Temple, Salt Lake City, UT 84102; (801) 531-0999; Fax: (801) 531-1003; E-mail:;

Utah Office of Tourism, 300 N. State Street, Salt Lake City, Utah 84114; (801) 538-1900 or (800) 200-1160;



Additional Resources

Lake Information

The Great Salt Lake Ecosystem Program within the Utah Division of Wildlife Resources conducts research, management, and conservation of Great Salt Lake wildlife resources focusing on brine shrimp harvest and related limnological and avian research.

The U.S. Fish and Wildlife Service’s Bear River Migratory Bird Refuge protects and manages 29,900 hectares (74,000 acres) for waterbirds and other wildlife.

Great Salt Lake Nature Center at Farmington Bay provides hands-on education opportunities for students and the general public “to foster curiosity, understanding, and pride in the Great Salt Lake Ecosystem among Utahns and the global community.

Great Salt Lake Institute at Westminster College “actively promotes partnerships among college and universities, industry, government agencies, and non-profit organizations interested in sustaining GSL as an important resource.

Great Salt Lake Information System is a coordinated effort between the Utah Division of Forestry, Fire and State Lands and Utah State University that gives GSL researchers and other interests a means to share knowledge and interact in ways that help preserve GSL resources.

The U.S. Geological Survey has a wealth of information on GSL including daily lake elevation data, salinity, habitat, and publications.

Reports, Plans, and Projects

Great Salt Lake Waterbird Survey Five-Year Report (1997-2001) is a comprehensive study of the waterbirds and the habitats they utilize at Great Salt Lake.

The Bear River Migratory Bird Refuge Field Report(.doc) gives detailed information about the refuge.

The Great Salt Lake Advisory Council was appointed by Governor Jon Huntsman, Jr. in 2008 to study current and future issues associated with Great Salt Lake and create a vision for future use.

The Utah Division of Forestry, Fire and State Lands owns and manages much of Great Salt Lake according to the Great Salt Lake Comprehensive Management Plan. The plan created the GSL Technical Team that provides “guidance and recommendations in the monitoring, management and research efforts of the Great Salt Lake ecosystem” and provides “a forum for the interchange of information on ideas, projects and programs that affect the activities and natural systems of the Great Salt Lake.”

Utah Department of Environmental Quality is developing water quality standards for GSL. A standard for selenium is complete, and work on assessing the health of freshwater wetlands near the GSL is ongoing.

Site Partners Information

Friends of the Great Salt Lake is a nonprofit organization dedicated to public education and conservation of GSL. 

Local chapters of the Audubon in Salt Lake City and Ogden, Utah lead public field trips around Great Salt Lake.

The Great Salt Lake Shoreland Preserve owned and managed by The Nature Conservancy provides the public an easily accessible means to explore and learn about Great Salt Lake marshes.

Utah Office of Tourism highlights unique travel opportunities for local and out of state tourists.


Aldrich, T. W. and D. S. Paul. 2002. Avian ecology of Great Salt Lake in Gwynn, J.W., ed. Great Salt Lake: an overview of change. Utah Department of Natural Resources Special Publication, p. 343-374.

Baskin, R. L. 2006. Calculation of area and volume for the north part of Great Salt Lake, Utah. U.S. Geological Survey Open-File Report 2006–1359. Accessed 10/13/09 at

Behle, W.H. 1958. The bird life of Great Salt Lake. Univ. of Utah Press, Salt Lake City.

Fellows, S., and T.C. Edwards, Jr. 1990. Temporal and spatial distribution of shorebirds at Great Salt Lake. Unpublished Progress Report, Utah Division of Wildlife Resources.

Governor's Office of Planning and Budget. 2008. 2008 Baseline Projections. Accessed 10/20/09 at

Hansen, K.S. 1991. Restoration and expansion of Bear River Migratory Bird Refuge, Brigham City, Utah, Environmental Assessment, USFWS, Denver, Colorado.

Jehl, J. 1988. Biology of the Eared Grebe and Wilson's Phalarope in the nonbreeding season: a study of adaptations to saline lakes. Studies in Avian Biology No. 12, Cooper Ornithological Society, 1988.

Paton, P.W.C. and T.C. Edwards, Jr. 1990. Status and nesting ecology of the Snowy Plover at Great Salt Lake--1990. Utah Birds, 6: 49-66.

Paton, P.W.C., C. Kneedy, and E. Sorensen. 1992. Chronology of shorebird and ibis use of selected marshes at Great Salt Lake. Utah Birds, 8: 1-19.

Paul, D. S. and A. E. Manning. 2002. Great Salt Lake waterbird survey: five-year report (1997-2001). Publication Number 08-38. Great Salt Lake Ecosystem Program, Utah Division of Wildlife Resources, Salt Lake City.