Established in 1911, this 46,460 acre Refuge consists of approximately 20,000 acres of open water surrounded by upland habitat of bunch grass, low sagebrush, and juniper. Small rocky islands in the lake provide nesting sites for the American white pelican, double-crested cormorant, and other colonial nesting birds. The upland areas serve as habitat for pronghorn antelope, mule deer, and sage grouse. Except for limited waterfowl hunting and pronghorn antelope hunting during the regular California State seasons, the Refuge is closed to public access to protect fragile habitats and to reduce disturbance to wildlife. The Clear Lake reservoir is the primary source of water for the agricultural program of the eastern half of the Klamath Basin with water levels regulated by the U.S. Bureau of Reclamation.