The Sierra Nevada red fox (Vulpes vulpes necator), also known as the High Sierra fox, is a subspecies of red fox found in the Oregon Cascades and the Sierra Nevada. It is likely one of the most endangered mammals in North America. The High Sierra fox shares most of its physical characteristics with the red fox, though it is slightly smaller and has some special adaptions for travel over snow. The High Sierra fox was discovered as a subspecies in 1937, but its study lapsed for more than half a century before its populations were rediscovered beginning in 1993. This subspecies of red fox may live up to 6 years.