California golden trout are native to two stream systems on the eastern side of the Kern River: Golden Trout Creek and the South Fork Kern River (Tulare County). Golden Trout Creek is thought to have once formed the headwaters of the South Fork Kern River but, due to volcanic activity thousands of years ago, it was diverted west near Tunnel Meadow and now flows directly to the Kern River.
The South Fork Kern River is quite large and flows from the western crest of the Sierra Nevada, near Cottonwood Pass, downstream to the Kern River where Lake Isabella now exists. It is unknown how far downstream California golden trout were historically distributed and the only documentation is from longtime Kernville resident, Ardis Walker. As a boy, fishing the South Fork Kern River in 1913, he reported catching California golden trout in the "gorge" just upstream of the Bloomfield Ranch, near the southern boundary of the Domeland Wilderness. It is thought that California golden trout may have extended downstream of Lake Isabella prior to the construction of Isabella Dam. The lower limits of their range probably changed depending on climatic conditions and seasonal water temperatures. It is unknown whether California golden trout naturally occurred in the Kern River, although it is likely that some level of movement occurred between these formerly connected rivers.
Due to their singular beauty and popularity as a unique sport fish, California golden trout have been widely distributed outside their native range, mostly in high elevation lakes and streams in the Sierra Nevada. They were also transplanted to numerous lakes in the Wind River Range in Wyoming. In about 1872, according to an old newspaper account, a transplant was made from Golden Trout Creek into the headwaters of Mulkey Creek. Although Mulkey Creek is a tributary to the South Fork Kern River, a natural barrier prevented movement of California golden trout into the headwaters. This area, Mulkey Meadows, was probably fishless until the 1872 transplant.
In 1876, 13 golden trout from Mulkey Creek were put into a “coffee can,” carried over the divide, and stocked into Cottonwood Creek; 12 survived the trip. Cottonwood Creek drains the eastern side of the Sierra Nevada to the Owens Valley and was fishless prior to the transplant. Later, trout from Cottonwood Creek were transplanted into Cottonwood Lakes, creating broodstock for almost all subsequent propagation and distribution of California golden trout throughout California and beyond.