Endangered and Threatened Wildlife and Plants; Final Rule To List the Sierra Nevada Distinct Population Segment of the California Bighorn Sheep as Endangered

We, the U.S. Fish and Wildlife Service (Service), determine endangered status pursuant to the Endangered Species Act of 1973, as amended (Act) for the Sierra Nevada distinct population segment of California bighorn sheep (Ovis canadensis californiana). This species occupies the Sierra Nevada of California, where it is known from five disjunct subpopulations along the eastern escarpment of the Sierra Nevada, and thought to total no more than 125 animals. All five subpopulations are estimated to be very small and are threatened by mountain lion (Felis concolor) predation, disease, naturally occurring environmental events, and genetic problems associated with small population size. We emergency listed this population segment of California bighorn sheep on April 20, 1999. The emergency listing was effective for 240 days. Immediately upon publication, this action continues the protection provided by the temporary emergency listing.