In the early part of the 1900s the King of Arizona (KOFA) Mine scoured this land for precious mineral deposits. Today, in a twist of fate, the Kofa National Wildlife Refuge (Refuge)protects the region's precious plant and animal life, including: one of the Arizona's largest desert bighorn sheep populations, a species nearly extirpated prior to the Refuge's establishment in 1939; less than 100 California fan palms, remnants of wetter days; and the rare Kofa Mountain barberry, found only in southwest Arizona. Approximately 82% of the Refuge has been designated as Wilderness, making this Arizona's second largest. In the north lie the Kofa Mountains, to the south the Castle Dome Mountains. Both are magnificently jagged peaks looming thousands of feet above the pristine desert floor of King Valley, which separates them.