Dry lake

Lore & Background

Dry lakes are formed when rain or groundwater flows into a depression, creating a temporary pond or lake. If total annual evaporation exceeds total annual inflow, the water disappears, leaving behind precipitated salts that build up over time. The resulting surface is a flat bed of clay, often encrusted with evaporite minerals such as sodium carbonate and borax. In deserts, dry lakes may be ringed by bajadas. Many dry lakes contain shallow water during the rainy season. If the water layer is thin and moved by wind, an exceedingly hard and smooth surface develops. Thicker water layers produce cracked-mud surfaces and teepee structure desiccation features. The Racetrack Playa in Death Valley features sailing stones, which move across the surface due to a precise combination of water depth, ice formation, and wind. Dry lake beds are typically devoid of vegetation but are ringed by salt-tolerant plants like shadscale and saltbrush. Threats include pollution from cattle feedlots, agricultural runoff, overgrazing, and the invasive shrub Kochia prostrata.

Reader's Guide

Dry lake beds are significant as unique geological and ecological features in arid regions worldwide. They preserve evidence of past water bodies and serve as important habitats for rare species adapted to extreme conditions. Their flat, hard surfaces have made them valuable for human activities, including land speed record attempts at Bonneville Salt Flats and Black Rock Desert, air bases such as Edwards Air Force Base and Groom Lake, and mineral extraction from subsurface brines. The Burning Man event is held annually on a playa in the Black Rock Desert. Under United States law, playa lakes may be considered isolated wetlands eligible for conservation programs.

Did You Know?

• The Racetrack Playa in Death Valley features sailing stones that move due to ice panels blown by wind.
• The term 'playa' is Spanish for 'beach' and is used in parts of Mexico and the western United States.