They are closely related and are classified as a subspecies of their distant relative, the rainbow trout, Oncorhynchus mykiss. They are the most brilliantly colored, have the least number of black spots and have been transplanted to many other lakes and streams of the Sierra Nevada and elsewhere. Earlier this century, angling on the Kern River had a worldwide recognition because of the presence of numerous, large native rainbows. The Kern River rainbow is much less colorful than golden trout, usually silvery with only a reddish lateral band, and is profusely covered with spots. However, they are able to develop golden trout coloration when transplanted to small, high elevation streams and allowed to reproduce for several generations.
Efforts are currently underway to restore their populations.
The story of the recovery of the Little Kern golden trout has been a particularly successful one and is the main topic of this article. The Little Kern River is a western tributary of the Kern River, lying at 6,000-10,000 feet of elevation, primarily in the Sequoia National Forest and Sequoia National Park in eastern Tulare County. There are about 100 miles of stream suitable for trout and 11 small lakes in this drainage. Most Little Kern tributaries flow about one cubic foot per second after the heavy winter snow-pack has melted, with a total of about 25 cubic feet per second for the drainage. The Little Kern golden trout originally occupied most of this drainage and was found nowhere else on earth.