PROTECTION STATUS: Threatened (Mojave population); not listed (Sonoran population)
YEAR PLACED ON LIST: 1990 (Mojave population)
CRITICAL HABITAT: 6.4 million acres in California, Nevada, Utah, and Arizona designated in 1994
RANGE: Southern California, southern Nevada, southwestern Utah, and extreme northern Arizona (Mojave population); lower elevations of Arizona (Sonoran population)
THREATS: Livestock grazing and off-road vehicle use, road construction, urban development, agriculture, introduced diseases, and predation by ravens and feral dogs
POPULATION TREND: Since the early 1970s, biologists have noted that desert tortoise populations are declining; populations have declined by as much as 90 percent since the 1980s.