Great Salt Lake supports a rich and dynamic biological system of regional, national and global importance. The amazing abundance of bird life at Great Salt Lake has earned its designation as a Western Hemisphere Shorebird Reserve Network site (1991). Birds of regional, national and international significance are drawn to its 15,000 square miles of various water environments, remote islands and shorelines, and about 400,000 acres of wetlands. Every year ten million birds from 338 different species rely on the Lake to feast during their thousand mile or more migrations. While there, they enjoy a unique and safe sanctuary that supports numerous breeding populations. The ecology of life at Great Salt Lake is an extraordinary example of the rich web of relationships between land and water, food and survival.

Great Salt Lake is a terminal lake with no outlet. Over time lake levels and salinity change dramatically depending on the level and quality of freshwater inputs from the Bear, Weber/Ogden, and Jordan River systems in tandem with seasonal evaporation rates. The geography of the Lake combined with man-made causeways, create a diversity of lake environments varying from the extremely salty North Arm (almost 28%), to the nearly freshwater Farmington Bay. Such diverse water environments are connected to expansive playas, shorelines and uplands to create excellent habitats for innumerable plants, invertebrates, reptiles, amphibians, mammals, and birds.

This animation captures the changing elevations of Great Salt Lake over a period of 46 years (1972 - 2018). During this time, the Lake’s mean average elevation fluctuated from a 12’ increase (1972 - 1986-87) to a 17.1’ decrease  (1989- 2018). On May 11, 2021, the average mean elevation of Great Salt Lake was 4,192.5’. This is down 0.1’ from March 2021 and down 2.0’ from March 2020. Currently, the Lake’s elevation is within 1.2’ of the historic low of 4,191.35’ (1963). During warm summer months, the elevation will bump up against this record low. 

Basic Lake Facts:

  • On an average year, GSL covers 1,700 square miles with a maximum depth of 33 feet. Current Lake elevation information is available from USGS for gauges at Saltair (South Arm) and Saline (North Arm). Additional USGS elevation data is available
  • Water enters Great Salt Lake via direct precipitation, Bear, Weber, and Jordan Rivers, and internal springs. The Great Salt Lake watershed is over 21,000 square miles.
  • Water entering Great Salt Lake carries dissolved minerals. When the water evaporates, it leaves those minerals and salts behind, resulting in salty water.
  • Great Salt Lake salinity varies across the Lake and is typically 3 to 5 times saltier than the ocean.
  • The Union Pacific Railroad Causeway divides Great Salt Lake into North and South Arms with vastly different ecosystems on either side.
  • The notorious "Lake Stink" is largely attributed to human-caused nutrient loading in Farmington Bay.
  • 75% of Utah's wetlands are located in the Great Salt Lake ecosystem.
  • Over 7 million migratory birds stop at GSL each year to feed, nest, and rest.
  • The Lake is alive! Bacteria, algae, zooplankton, microbialites, brine shrimp, and brine flies form an important food web.
  • Brine shrimp harvest and mineral extraction industries at Great Salt Lake are worth millions of dollars.
  • The Great Salt Lake ecosystem is popular for wildlife viewing, boating, swimming, and hiking. It attracts visitors from around the world.

For more information, visit our Weblinks page for a listing of links organizations working with Great Salt Lake.

Great Salt Lake Level Matrix

Click to enlarge image.

GSL Planning Matrix

 Lake Fact Sheets

Life Forms at Great Salt Lake

10 Myths About Great Salt Lake

Wetlands Watch

Physical Features of Great Salt Lake

Biotic Features of Great Salt Lake

What's That Smell?

Assessment of Potential Costs of Declining Water Levels in Great Salt Lake — November 2019

"Policy solutions and investments in water for Great Salt Lake now can prevent future costs to the region. The magnitude of potential consequences, $25.4 billion to $32.6 billion over twenty years, suggests that major interventions are likely warranted. The science review and economic analyses in this study indicate that reduced lake levels at Great Salt Lake are already imposing adverse conditions and economic costs on the regional community and economy. The continued trajectory of declining lake levels will likely only increase the magnitude and expand the categories of costs imposed on Utahns."

Study by ECONorthwest and Martin & Nicholson Environmental Consultants prepared for the Great Salt Lake Advisory Council

Read the assessment here

Great Salt Lake Research — Good Science Informs Good Management

The GSL ecosystem is a complex and unique saline ecosystem that is locally, regionally, hemispherically, and globally important. It provides a valuable mix of habitats from islands, open water, wetland complexes and uplands for native plant and wildlife populations. It also provides critical resting, staging, and nesting capacity for over 260 avian species and millions of migratory birds.

The Lake is an important economic contributor to the State of Utah through a variety of ecosystem services that include mineral extraction, brine shrimp, recreation, and tourism among others. It provides $1.3 B annually to the State’s economy.

The Division of Forestry, Fire and State Lands in the Department of Natural Resources has jurisdictional responsibility for managing the Lake sustainably for future generations. The system is a hotbed of potential research opportunities that can help inform effective management decisions toward that end.

What follows are examples of some of the resources that are in place to help identify research needs and fund proposals that generate valuable science and insights about the system. These serve to increase our understanding so we can work to protect Great Salt Lake.

Meetings for all of these standing bodies are open to the public. We encourage you to attend these meetings and share your voice. In addition to good science, good management is informed by a well-educated community.

Utah Division of Forestry, Fire & State Lands
Additional Great Salt Lake Organizations