The Amargosa Range is a mountain range in Inyo County, California, San Bernardino County, California and Nye County, Nevada. The 110-mile range runs along most of the eastern side of California's Death Valley, separating it from Nevada's Amargosa Desert. The U-shaped Amargosa River flows clockwise around the perimeter of the range, ending 282 f…The Amargosa Range is a mountain range in Inyo County, California, San Bernardino County, California and Nye County, Nevada. The 110-mile range runs along most of the eastern side of California's Death Valley, separating it from Nevada's Amargosa Desert. The U-shaped Amargosa River flows clockwise around the perimeter of the range, ending 282 feet below sea level in the Badwater Basin.