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About the Lake

UGS Map from Commonly Asked Questions about Great Salt Lake

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 1,700 square miles of various water environments, remote islands, and shorelines, and about 360,000 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. Great Salt Lake's ecology 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 quantity and quality of freshwater inputs from the Bear, Weber/Ogden, Jordan River, and groundwater 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 (about 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.

The management of Great Salt Lake's water, land and wildlife is a collaboration between many state and federal agencies, non-profit organizations, and private land-owners. In 2023, the Great Salt Lake Commissioner's Office was established to increase collaboration and cooperation between the many stakeholders. The Commissioner's Strategic Plan establishes a target elevation range for Great Salt Lake of 4198'-4205' above sea level, a range that balances the wide variety of ecological, economic, and recreational interests detailed in the Great Salt Lake Elevation Matrix.

This animation captures the changing elevations of Great Salt Lake over a period of 38 years (1984-2022). The Lake’s elevation fluctuated from a 12 foot increase (1972-1986) to a 23 foot decrease (1989-2022). Because Great Salt Lake's average depth is only 15 feet, each foot of elevation change translates into a huge difference in surface area.

In October 2021, Great Salt Lake's South Arm surface elevation dropped to 4,190.2 feet above sea level, superseding the 1963 historic low of 4,191.35 feet. In November 2022, it reached another new record low elevation of 4,188.5 feet above sea level. In July, 2024, after two record-breaking water years, the current South Arm elevation is 4194.1 feet - a significant improvement from levels in 2022, but still 4 feet below the target range.

As water levels decline, the Lake's salinity concentrates. A healthy salinity range for Gilbert Bay (Great Salt Lake's South Arm) is between 13-15%. In 2022, Gilbert Bay reached 19% salinity, approaching the maximum threshold that brine shrimp and brine flies are able to tolerate. Both declining water levels and rising salinity threaten the Lake's food web and the millions of migratory birds who depend on this ecosystem.

A drying Great Salt Lake has local and regional consequences including increased dust, worse air quality, reduced snow, reduced Lake access, habitat loss, island bridges, more invasive plant growth, and negative economic consequences to the state. By protecting the Lake, we help our economy, environment, wildlife, and future.

Basic Lake Facts

  • At an average elevation of 4,200 feet above sea level, Great Salt Lake's surface area is 1,700 square miles with a maximum depth of 33 feet. At the 2022 record low elevation of 4,188.5 feet, Great Salt Lake's surface area was approximately 888 square miles. Current Lake elevation information is available from USGS for gauges at Saltair (South Arm) and Saline (North Arm). Explore the USGS Great Salt Lake Hydromapper for more water level and salinity data.
  • Water enters Great Salt Lake via direct precipitation, the 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, including salts. When the water evaporates, it leaves those minerals behind, resulting in salty water.
  • The Union Pacific Railroad Causeway divides Great Salt Lake into North and South Arms with vastly different ecosystems on either side. The Lake's North Arm (Gunnison Bay) is cut off from most freshwater inflows and is about twice as salty as the South Arm. Only halophilic bacteria and archaea can survive in this hypersaline environment, and their reddish pigment can make the water appear pink.
  • Salinity varies across the Lake and in response to water levels. A healthy salinity range for Gilbert Bay (Great Salt Lake's South Arm) is 13-15%, about 3-5 times saltier than an ocean. In 2022, Gilbert Bay reached 19% salinity, approaching the maximum threshold that brine shrimp and brine flies can tolerate.
  • The notorious "Lake Stink" is produced by bacteria living in lakebed sediments. These bacteria play an important role in the ecosystem, breaking down and recycling nutrients like nitrogen. Much of the smell we experience is the result of human-caused nutrient loading in Farmington Bay. Water flowing into Farmington Bay contains excessive nutrients from agriculture, industry, and sewage treatment which fuel algal blooms. Decomposition of that algae in turn fuels bacterial growth and their production of hydrogen sulfide gas.

Visit our Additional Resources page to view more organizations working with Great Salt Lake.

FRIENDS of Great Salt Lake - About the Lake