Walker Lake (Nevada)

Walker Lake is a natural lake, 50.3 mi² (130 km²) in area, in the Great Basin in western Nevada in the United States. It is 18 mi (29 km) long and 7 mi (11 km) wide, located in northwestern Mineral County along the eastern side of the Wassuk Range, approximately 75 mi (120 km) southeast of Reno. The lake is fed from the north by the Walker River and has no natural outlet except absorption and evaporation.

The lakebed is a remnant of prehistoric Lake Lahontan that covered much of northwestern Nevada during the ice age. Although the ancient history of Walker Lake has been extensively studied by researchers seeking to establish a climatic timeline for the region as part of the Yucca Mountain Nuclear Waste Repository study, this research has raised many puzzling questions. Unlike Pyramid Lake, the lake itself has dried up several times since the end of the Pleistocene, probably due to natural diversions of the Walker River into the Carson Sink. Also, this research found no evidence that the Walker Lake basin contained water during the Lake Lahontan highstand, although based on the surface elevation of the highstand evidenced elsewhere in the region it must have.

Walker Lake is the namesake of the geological trough in which it sits, and which extends from Oregon to Death Valley and beyond, the Walker Lane.

In the 19th century the area around the lake was inhabited by the Paiute. Extensive use of the water of the Walker River and its tributaries for irrigation since the late 19th century has resulted in a severe drop in the level of the lake. According the USGS, the level dropped approximately 140 ft (40 m) between 1882 and 1994.

The lower level of the lake has resulted in a higher concentration of stream pollutants. As of 2004 the salt concentration is above the lethal limit for most of the native fish species throughout much of the lake, and the survival of the Lahontan cutthroat trout in the lake will be threatened if inflow is not drastically increased. Also affected are the lake's Tui chub. In 2009, the town of Hawthorne canceled its Loon Festival because the lake, once a major stopover point for migratory loons, could no longer provide enough chub and other small fish to attract many loons.

The Walker Lake State Recreation Area is located along the western shore of the lake. The Hawthorne Army Depot, which claims to be the world's largest ammunition depot, fills the valley to the south of the lake. U.S. Route 95 passes along the western shore of Walker Lake.