Eagle Lake trout, Oncorhynchus mykiss aquilarum, is endemic to Eagle Lake

Eagle Lake (Lassen County)

Eagle Lake is a lake in Lassen County approximately 15 miles north of Susanville, California. It is the second largest natural lake entirely in the state of California, United States....

, in Lassen County, California

Lassen County, California

Lassen County is a county located in the northeastern portion of the U.S. state of California. As of the 2010 census, the population was 34,895, up from 33,828 at the 2000 census...

. It is a type of trout

Trout

Trout is the name for a number of species of freshwater and saltwater fish belonging to the Salmoninae subfamily of the family Salmonidae. Salmon belong to the same family as trout. Most salmon species spend almost all their lives in salt water...

, known for its ability to withstand high alkalinity

Alkalinity

Alkalinity or AT measures the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution...

, that looks similar to rainbow trout

Rainbow trout

The rainbow trout is a species of salmonid native to tributaries of the Pacific Ocean in Asia and North America. The steelhead is a sea run rainbow trout usually returning to freshwater to spawn after 2 to 3 years at sea. In other words, rainbow trout and steelhead trout are the same species....

.

Range

The Eagle Lake trout name comes from its former exclusive-endemic Eagle Lake territory. The lake's trout population was thought to be extinct. A few were discovered in the lake in 1958, and the propagated and California Department of Fish and Game

California Department of Fish and Game

The California Department of Fish and Game is a department within the government of California, falling under its parent California Natural Resources Agency. The Department of Fish and Game manages and protects the state's diverse fish, wildlife, plant resources, and native habitats...

planted 5,000 of the trout in the lake. While formerly only in Eagle Lake, the Department of Fish and Game has transplanted the Eagle Lake trout into dozens of lakes in California.