The Kofa Wilderness now contains a total of 547,719 acres and is managed by the Fish & Wildlife Service's Kofa National Wildlife Refuge. All of the Wilderness is in the state of Arizona. In 1990 the Kofa Wilderness became part of the now over 110 million acre National Wilderness Preservation System.

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.

The Kofa Refuge and Wilderness is located between Yuma and Quartzsite, Arizona east of U.S. Highway 95. The southernmost of the five entrance roads is found about 40 miles north of Yuma and leads to the southern Castle Dome Mountains. Other popular entrances are located at King Valley, Palm Canyon, and Crystal Hill, which is the northernmost entrance 10 miles south of Quartzsite. An entrance off U.S. Interstate 10 at the Vicksburg Road provides access to the northeast corner of the Refuge.

Old roads, remnants from the mining era, connect all areas of the Refuge so pioneering individuals can negotiate throughout the Refuge from north to south or east to west. Four-wheel drive vehicles are a must; some of the more remote sections of the Refuge will take 3 - 4 hours of driving to reach from the highway.

There are no visitor facilities on the Refuge; the nearest gas stations, restaurants, and motels are found in Yuma or Quartzsite. The Refuge Office is also in Yuma situated at 9300 E. 28th Street.