An exception to the general rule concerning trout species composition and distribution is found in Cottonwood Creek, which flows easterly into Fish Lake Valley from near White Mountain Peak. In 1946, when Department of Fish and Game and U.S. Forest Service biologists noted that the Paiute Cutthroat Trout, Oncorhynchus clarki seleniris (Snyder), populations of the upper East Fork Carson River (Alpine County, California) were seriously threatened, a limited number were planted in the previously fishless upper North Fork Cottonwood Creek. This stream has been generally closed to angling since that time. The subspecies is currently listed as threatened under the federal Endangered Species Act.
The North Fork Cottonwood Creek Paiute Cutthroat population is perhaps the only genetically pure population left in the world, and it is being protected as part of the recovery plan for the subspecies. Should the subspecies recover sufficiently, management plans may allow a very limited harvest. Until that time, however, the North Fork Cottonwood Creek will remain closed to angling. To accelerate the recovery of the Paiute Cutthroat Trout, it may be spread to other suitable streams as part of a plan under consideration by the Department of Fish and Game and the U.S. Forest Service. At present, however, the only stream area in the White Mountains with a special restriction is the North Fork Cottonwood Creek. Anglers planning to fish anywhere in California should check current fishing regulations, which are available at most sporting goods stores.