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.

- Location: Harney County, Oregon

- Surface elevation: 4078 ft|m}}

- Inflow: Geothermal springs

- Outflow: Ground seepage and evaporation

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. After the population recovered, the U.S. Fish and Wildlife Service removed the Borax Lake chub from the federal endangered species list in July 2020. Federal officials planned to monitor the fish for 10 years after delisting. Oregon's Fish and Wildlife Commission removed it from the state threatened and endangered species list in February 2021. The lake and nearby wetlands and water bodies such as Alvord Lake, north of the small community of Fields, provide important bird habitat.

Lake facts (Wikipedia):

- Surface area: 10 acre|ha}}

Source: https://en.wikipedia.org/wiki/Borax_Lake_(Oregon) (Wikipedia / Wikimedia, CC BY-SA). Verify access, seasons, and regulations with the land manager before visiting.

List note: an alkali lake in Harney County, home to the Borax Lake chub Map / bathymetry image: https://commons.wikimedia.org/wiki/Special:FilePath/%7C_caption_bathymetry_____%3D?width=1600