The Sierra Nevada red fox (Vulpes vulpes necator), also known as the High Sierra fox, is a subspecies of red fox and likely one of the most endangered mammals in North America. The fox's Sierra Nevada Distinct Population Segment is estimated at 29 adults near Sonora Pass in California. The Southern Cascades Distinct Population Segment consists of an estimated 42 adults near Lassen Volcanic National Park and an unknown number of individuals in five areas of Oregon. No other populations are known. Interbreeding with non-native red foxes and recruitment success are primary conservation concerns.