Great Salt Lake

The Great Salt Lake, in the basin of the ancient Lake Bonneville in northern Utah, is the largest saltwater lake in the Western Hemisphere — a vast, terminal, endorheic lake of extraordinary ecological importance, supporting concentrations of migratory birds that rank among the greatest in North America. The lake’s extreme salinity (10-27%, varying by location and water level) prevents fish but supports astronomical numbers of brine shrimp and brine flies, which in turn fuel the migration of millions of shorebirds and waterfowl along the Pacific Flyway.

The Great Salt Lake is in a crisis of water level decline — the lake surface has dropped approximately 11 feet since the 1980s, exposing vast areas of toxic dust-generating lakebed and threatening the brine-shrimp ecosystem upon which millions of migratory birds depend. The lake’s ecological and cultural significance is immense; its ecological threat is severe. The Great Salt Lake is a treasured natural icon of Utah and of the American West.

Spring (April and May) brings the peak bird migration — American avocets, black-necked stilts, Wilson’s phalaropes (sometimes a million birds in the south arm in May), marbled godwits, long-billed dowitchers, and the full complement of Pacific Flyway migrants concentrate at the lake’s margins. Late summer (August and September) brings the extraordinary eared grebe and Wilson’s phalarope concentrations (the south arm holds a globally significant fraction of these species’ total world population in August and September). Fall for the migrating waterfowl at Bear River. Spring for the avocets and phalaropes, and late summer for the grebes, are the peak spectacles.

The Great Salt Lake is one of the most important migratory-bird habitats in North America — the south arm concentrates globally significant fractions of the total world populations of Wilson’s phalarope, eared grebe, American avocet and other species. In August and September, an estimated 5-10 million birds use the lake system. American avocets, black-necked stilts, marbled godwits, long-billed dowitchers, dunlin, and dozens of other shorebird species concentrate at the lake margins in spring and fall. Bear River Migratory Bird Refuge (at the north end) is one of the finest waterfowl refuges in the continental United States, with tundra swans, snow geese, canvasbacks and other species in fall. Brine shrimp and brine flies — the lake’s primary productivity — support all of this bird life.

Swimming in the Great Salt Lake is safe but carries specific considerations: the extreme salinity will sting eyes and open cuts severely (do not get brine in your eyes; rinse immediately with fresh water if you do); shower immediately after swimming to remove the brine (the salt will crystallize on skin and be uncomfortable if not rinsed off; shower facilities are available at the swimming areas). The exposed lakebed (in areas where the lake has receded) generates toxic dust — if dust storms are occurring near the lake, avoid prolonged exposure. Brine flies are abundant in summer at the lake edge (not biting; just present in large numbers — a brief annoyance). Respect the brine in eyes, the shower requirement and the dust-storm caution.

The Great Salt Lake offers birding (the primary ecological draw — Farmington Bay, Bear River Migratory Bird Refuge, Antelope Island and other lake-margin sites concentrate millions of migratory birds in spring and fall; the lake is one of the most important Pacific Flyway stopover sites in North America), swimming in the hypersaline brine (the extreme buoyancy of the brine — much saltier than the ocean — makes it nearly impossible to sink; the Antelope Island and Great Salt Lake State Marina swimming beaches offer this remarkable experience), birdwatching at the Bear River Migratory Bird Refuge (the finest waterfowl refuge in Utah, at the north end of the lake), the Spiral Jetty (Robert Smithson’s 1970 earthwork in the north arm of the lake — now exposed and pink-colored by halophilic bacteria — one of the greatest Land Art works in the United States), kayaking the lake margins, and the annual Great Salt Lake Bird Festival (in May, the largest birding festival in Utah). The birding spectacle, the buoyant swimming, and the Spiral Jetty are the singular draws.

The Great Salt Lake is the modern remnant of prehistoric Lake Bonneville — the vast Pleistocene lake (approximately the size of Lake Michigan) that occupied the Great Basin at its maximum about 15,000 years ago. The Bonneville shoreline (visible as wave-cut terraces on the Wasatch Front mountains) marks the ancient lake’s maximum extent. John C. Frémont was the first American explorer to reach the Great Salt Lake (1843), initially fearing he had reached the Pacific Ocean. The lake’s role in the settlement of Utah by the Church of Jesus Christ of Latter-day Saints (the Mormon pioneers arrived in the Salt Lake Valley in 1847) has made it a cultural icon. The Transcontinental Railroad was completed at Promontory Summit on the north shore in 1869. The lake level has fluctuated dramatically over historical time — the 1980s floods and the current extreme low are both on record.

The Great Salt Lake is a terminal, endorheic lake — no outlet exists; all water that enters the lake (from the Jordan, Weber and Bear rivers) can only leave by evaporation, concentrating the dissolved salts. The salinity varies dramatically: the north arm (isolated by the Union Pacific Railroad causeway since 1959) is 25-27% salinity and pink-colored by halophilic (salt-loving) archaea and bacteria; the south arm is 10-15% salinity. The Bonneville Salt Flats (northwest) are the evaporite remnant of the prehistoric lake. The lake level is controlled by the balance of river inflow and evaporation; the current decline is driven by over-appropriation of the tributary rivers for agriculture and urban use. The exposed lakebed generates toxic dust storms (laden with arsenic, lead and other heavy metals from the dried lake sediments) that affect Salt Lake City.

The Great Salt Lake is in a severe ecological crisis: the lake level has dropped approximately 11 feet since the 1980s (the lowest recorded level in 170 years of observation), driven primarily by over-appropriation of the lake’s tributary rivers for agriculture and urban water supply. The declining water level is reducing the brine-shrimp habitat, concentrating the salinity beyond brine-shrimp tolerance in the south arm, and exposing the toxic lakebed to wind erosion. The loss of the lake’s brine-shrimp productivity would devastate the millions of migratory birds that depend on the lake for fuel. The lake’s ecological decline is one of the most serious conservation crises in the American West. The Utah Legislature has passed water conservation measures, but the lake level continues to decline. This is among the most urgent conservation issues in the United States.

The Great Salt Lake holds an iconic place in the cultural identity of Utah and the American West — the vast inland sea that greeted the Mormon pioneers in 1847, a globally unique hypersaline lake ecosystem, the world’s finest setting for the Land Art masterpiece of the Spiral Jetty, the site of the Transcontinental Railroad completion, and now the subject of urgent conservation concern as its water level falls to historic lows. Its ecological crisis has made it a symbol of the consequences of water over-appropriation in the arid West. The Great Salt Lake is a treasured natural and cultural icon of Utah.

The Great Salt Lake is accessible from multiple points: Antelope Island State Park (on the south arm, via I-15 exit 335 — the most popular lake-access point), the Great Salt Lake State Marina (on the south shore near Magna, via I-80 west from Salt Lake City), and the Bear River Migratory Bird Refuge (at the north end, near Brigham City). The Spiral Jetty (on the northeast shore, near Promontory Point) requires a 16-mile unpaved road from UT-83 (passable by most vehicles in dry conditions). Salt Lake City (5-30 miles from various access points) has full services. Check Utah State Parks for Antelope Island fees and conditions; the USFWS for Bear River access.

The Great Salt Lake’s conservation crisis is the most critical ecological issue in Utah. The primary conservation action needed is reducing water appropriation from the lake’s tributary rivers — this requires political and agricultural policy change. Individual visitors can help by: supporting Utah water conservation policies and organizations (The Nature Conservancy, Great Salt Lake Collaborative); minimizing personal water use in the Salt Lake watershed; visiting Antelope Island, Bear River and the Spiral Jetty to build awareness and political support for lake conservation; not disturbing any shorebird or waterfowl concentrations; and packing out all trash from any lake-access area. Every acre-foot of water that remains in the lake instead of being diverted is a conservation victory.

Antelope Island State Park: Utah State Parks vehicle fee required. Great Salt Lake State Marina: Utah State Parks fee. Bear River Migratory Bird Refuge: USFWS free (open during daylight hours). Spiral Jetty: BLM free access (unpaved road; check road conditions). No collecting of organisms or minerals. No disturbing of shorebird or waterfowl concentrations. Pets on leash in all state-park and refuge areas. Pack out all trash. Check each access point’s managing agency for current hours, fees, road conditions and bird-activity reports before visiting.

Antelope Island State Park (the primary lake-access park, with the bison herd and the shorebird spectacle), the Spiral Jetty (Robert Smithson’s earthwork at the northeast corner of the lake — one of the greatest works of American Land Art, now surrounded by the pink hypersaline north arm), Bear River Migratory Bird Refuge (at the north end, one of the finest waterfowl refuges in North America), the Bonneville Salt Flats (the prehistoric lake’s evaporite remnant, 60 miles west), and Salt Lake City (Utah’s capital) define the Great Salt Lake experience. The lake, the Antelope Island bison, and the Spiral Jetty together constitute one of the finest and most unique landscape experiences in the American West.

Visit Bear River Migratory Bird Refuge in mid-October for the tundra swan migration — thousands of tundra swans stop at Bear River on their way south from Alaska to their wintering grounds, and the sight of white swan flocks against the Great Salt Lake and the Wasatch mountains is extraordinary. Visit Antelope Island in late August for the eared-grebe concentration on the south arm (check the Great Salt Lake waterbird survey website for the current grebe count — sometimes 5 million birds are on the lake). Drive the unpaved road to the Spiral Jetty for the finest Land Art experience in the West — walk the basalt-rock spiral into the pink, perfectly still water of the north arm and understand why it is considered one of the masterworks of 20th-century American art.