Summer 2014 417 California Fish and Game 100(3):417-435; 2014 The historical distribution of bighorn sheep in the Sierra Nevada, California JOHN D. WEHAUSEN* AND FRED L. JONES White Mountain Research Center, University of California, 3000 East Line Street, Bishop, CA 93514, USA (JDW) 1721 Grouse Ridge Trail, Cool, CA 95614, USA (FLJ) *Correspondent:
[email protected] Bighorn sheep in the Sierra Nevada disappeared from most of their historic range, surviving in only 3 populations west of the town of Independence in the Owens Valley. As a primary basis for restoration of these sheep, we compiled historical sightings and skull remains for Sierra Nevada bighorn sheep by twelve geographic regions, along with early estimates of population sizes where they existed. Historic sightings suggest that at least 10 populations survived to the twentieth century of which 2 persisted to the middle of that century before disappearing; but the sighting record does not distinguish viable populations from those that may have been declining to extinction. While it is possible for some populations to assign a decade when they disappeared, those populations may have lost viability earlier. Our data base probably represents the historical north-south distribution of these sheep and provides distributional details for some populations. However, it is remarkably sparse for some regions, suggesting that it may not have captured the full historical distribution of this animal, particularly west of the Sierra crest, where the earliest population losses may have occurred. Restoration efforts need to recognize this potential shortcoming. Key words: bighorn sheep, endangered species, historical distribution, Ovis canadensis sierrae, Sierra Nevada _________________________________________________________________________ Information on historical distribution is an important foundation for wildlife restoration programs.