The central portion of the Agua Fria mining district is about 3 miles east of Mayer, Yavapai County, Arizona. It is bisected by the Agua Fria River which flows from west to east. Most of sections 6, 7, and 18, T. 12 N., R. 2 E., and the eastern parts of sections 12 and 13, T. 12 N., R. 1 E. were examined during field investigations (Figs. 1 and 2).