Lake Size: 20 miles long 8 miles wide
Deepest Depth: 60 feet (18 m)
Latitude: 42.392222
Longitude: -121.880278
Lake Level Above Sea Level: 4140 ft (1262 m)
Counties: Klamath County
Cities: Klamath Falls

Information: Since 1917, the water level in the lake has been regulated by the United States Bureau of Reclamation as part of the Klamath Reclamation Project to support agriculture in the upper Klamath Basin. Prior to the 20th century the lake was surrounded by widespread marshes which were largely drained for cultivated land. The lake is naturally eutrophic, resulting in a high natural concentration of nutrients. In the 20th century, the augmentation of nutrients by agricultural runoff in the surrounding farming valley have caused the lake to become hypereutrophic resulting in blue-green algae blooms over the lake ( largely Microcystis aeruginosa and Aphanizomenon flos-aquae) The algae blooms turn the water an opaque green in the summer and afford little recreational use on the lake. State standards for dissolved oxygen are routinely violated. In 1988, two formerly abundant Upper Klamath Lake fish species, the Lost River sucker and the shortnose sucker (Catostomidae), were placed on the federal endangered species list. A drought in the summer of 2001 caused the Bureau to shut down the Klamath Project to protect the sucker population. The shutdown led to widespread protests among the ranching community and has become a national issue concerning property rights and environmentalism.