When construction was completed in 1917, it was the largest and best equipped hatchery in California and could produce 2,000,000 fish fry per year. Initially, fish eggs were collected from the
Rae Lakes and were transported to the hatchery by mule train. Since 1918, golden trout eggs have been collected from the Cottonwood Lakes. This program is the sole source of California golden trout eggs, currently operated by the nearby Black Rock Fish Hatchery since the closure of Mt Whitney Hatchery in 2008. In July 1931, the Mount Whitney Fish Hatchery and the Colorado Fish Commission traded 30,000
Colorado River cutthroat trout eggs for 25,000 golden trout eggs. The resulting Colorado cutthroat fry were planted in remote
High Sierra lakes at very high elevations. Over the following 50 years, the population in Colorado became endangered due to
habitat destruction and interbreeding with other species of trout. The cutthroats now living in California remained pure. In 1987, California and Colorado cooperated to transplant 50 genetically pure cutthroats back to a remote lake in
Rocky Mountain National Park, where they thrived. ==Proposed closure==