This report was prepared for the United States Air Force under an agreement t o compile and summarize available information on the geology, minerals and energy resources of the Luke Air Force Range. The primary focus of this investigation is to compile a general inventory of mineral production and mineral resources activity on the Luke Air Force Range (LAFR) . LAFR i s a wedge-shaped land area o f 2,673,156 acres lying in the southwestern corner o f Arizona and spanning portions o f Yuma, Maricopa and Pima Counties. The LAFR complex extends east-west between the communities of Ajo and Yuma, Arizona. Its northern boundary is formed by the Gila River Valley, a mainline of the Southern Pacific Railroad, and U.S. Interstate Highway 8. Limiting its southern extent is the International Boundary between the United States and Mexico. The eastern boundary is formed, in Maricopa County, by the Vekol Valley and the Papago Indian Reservation and, in Pima County, by the town of Ajo and the Organ Pipe Cactus National Monument. The Colorado River Valley forms its western boundary (Figure 1 ). LAFR has a maximum north-south dimension o f approximately 60 miles and an east-west dimension of approximately 130 miles. The LAFR complex is shown on parts, or all, of 44 United States Geological Survey quadrangle maps (Figure 2). Included within the boundaries of LAFR are the 825,440 acres comprising the Cabeza Prieta Game Range (Figure 1). The game range i s administrated by the United States Fish and Wildlife Service.