my brother an fellow adv (bucketboy) passed through there a few months ago
A U.S. Marine Corps permit is required for entry to the Barry M. Goldwater Range and is available from the Marine Corps Air Station, Yuma, Range Management Department (520-341-3402). El Camino del Diablo continues through the Cabeza Prieta National Wildlife Refuge. A permit from the U.S. Fish and Wildlife Service (Cabeza Prieta National Wildlife Refuge, Ajo, Arizona) is required to travel on the refuge (520-387-6483).
here you go
hope this helps