Global Range: It occurs in California (from Inyo County to San Diego and Imperial Counties), Nevada (southern Nye County, foothills of Charleston Mountains, and west of Davis Dam in Clark County), Utah (near St. George in Washington County), and Arizona (Mohave, Yuma, western Yavapai, western Maricopa, western Pinal, and western Pima Counties) (Benson 1969, Welsh 1993).