Eagle Lake (Lassen County)

Eagle Lake
The lake and its surroundings from a small peak above
Location	Lassen County, California
Coordinates	40°38′42″N 120°44′38″W / 40.64500°N 120.74389°W / 40.64500; -120.74389Coordinates: 40°38′42″N 120°44′38″W / 40.64500°N 120.74389°W / 40.64500; -120.74389
Catchment area	600 sq mi (1,600 km2)
Basin countries	United States
Surface area	24,000 acres (97.1 km2)
Max. depth	85 ft (26 m)
Surface elevation	5,098 ft (1,554 m)

Eagle Lake is a lake at 5,098 ft (1,554 m) elevation in Lassen County approximately 15 mi (24 km) north of Susanville, California. An endorheic alkaline lake, it is the second largest natural lake entirely in the state of California, United States.

Eagle Lake is home to osprey (Pandion haliaetus) and bald eagles (Haliaeetus leucocephalus), from which it gets its name.

Eagle Lake is the only watershed which supports native Eagle Lake trout (Oncorhynchus mykiss aquilarum). These rainbow trout grow to very large sizes, possibly having evolved to live longer as low flows often restrict spawning runs up their main spawning stream, Pine Creek. The average size of Eagle Lake trout are about 1.5 lb (0.68 kg) and can exceed 10 lb (4.5 kg). Adults quickly grow to a size of 17 to 18 in (43 to 46 cm) in three years and can live for up to 11 years. Since these Modoc Lakes are high in alkalinity, the trout have evolved to only be able to live in these lakes. These trout were once so abundant that there was a commercial fishery for them in the late 19th century. At the same time, extensive logging and heavy livestock grazing caused Pine Creek to change from a permanent to an intermittent stream in its lower reaches. In the early 1950s the few remaining eagle lake rainbow trout at the mouth of Pine Creek were rescued and used to start a hatchery program to maintain the species and the sport fishery. Because of the complete dependence of Eagle Lake rainbow trout on hatchery production, the American Fisheries Society considers it to be a threatened species and NatureServe has listed it as critically imperiled. Peter Moyle considers it to be one of the most endangered salmonids in California. However, a petition for listing the Eagle Lake rainbow trout as a threatened species was rejected by the U.S. Fish and Wildlife Service in 1994, and a similar petition was rejected by the California State Fish and Game Commission in 2004. From 2007 to 2009 Bogard Spring Creek, a tributary to Pine Creek, was electrofished to remove non-native brook trout (Salvelinus fontinalis).