Borax Lake

Borax Lake is a 10-acre (4.0 ha) alkaline lake in the Alvord Desert of southeastern Oregon in the United States. The lake is fed by geothermal springs 100 feet (30 m) below the surface that range in temperature from 104 to 300 F (40 to 149 C). Surface water temperatures usually range from 61 to 100 F (16 to 38 C) but occasionally go higher. The springs lie along the Steens fault zone, which runs north-south through the Alvord Valley east of Steens Mountain. The lake contains high concentrations of borax (sodium borate), as well as arsenic and lead. Despite this, it is home to a unique species of fish, known as the Borax Lake chub. The species was formerly threatened by development of geothermal energy in the vicinity. However, in 1993 The Nature Conservancy bought 160 acres (65 ha) of private land, including the lake, in order to protect it; the U.S. Fish and Wildlife Service has designated 640 acres (260 ha) near the lake as critical habitat, and the Steens Mountain Cooperative Management and Protection Act of 2000 put the area around the lake off-limits to geothermal exploration and mining. The lake and nearby wetlands and water bodies such as Alvord Lake, north of the small community of Fields, provide important bird habitat.