The Wilderness Act (Public Law 88-577, September 3, 1964) and related acts require the U.S. Geological Survey and the U.S. Bureau of Mines to survey certain areas on Federal lands to determine their mineral resource potential. Results must be made available to the public and be submitted to the President and the Congress. This report presents the results of a geochemical survey of the Arnold Mesa Roadless Area (U.S. Forest Service number 03092) in the Prescott and Tonto National Forests, Yavapai County, Arizona. The Arnold Mesa Roadless Area was classified as a further planning area during the Second Roadless Area Review and Evaluation (RARE II) by the U.S. Forest Service, January 1979.

During 1980 the U.S. Geological Survey and the U.S. Bureau of Mines (USBM) conducted field investigations to evaluate the mineral resource potential of the Arnold Mesa Roadless Area, Yavapai County, Arizona. Field studies included geologic mapping (Wolrfe, 1983), aeromagnetic mapping (Davis and Wolfe, 1983), geochemical sampling (this report), and a survey of known mines and prospects (McColly and Korzeb, 1981).

The Arnold Mesa Roadless Area comprises about 28,000 acres (11,300 hectares) in and along the flanks of the Black Hills south of Camp Verde, Arizona. The Black Hills form a northwest-trending drainage divide, between the Agua Fria drainage on the west and Verde River on the east, that extends through the roadless area. The crest and southwest flank of the divide within the study area are moderately dissected, gently rolling uplands. The northeast flank is steep terrain that forms the western wall of the Verde Valley. The northeast flank has a total relief within the study area of almost 4,000 ft (more than 1,200 m) and is deeply incised by the canyons of Gap and Chasm Creeks. Unpaved roads provide access to much of the perimeter of the Arnold Mesa Roadless Area, but the interior is accessible only by foot, horse, or helicopter.