Completely accessible, this unit is the eastern half of the Cabeza Prieta National Wildlife Refuge along the Mexican border and is nearly all wilderness. Only desert bighorn sheep are hunted here and can grow to over 180 inches. Backpack or horseback hunting is recommended. Illegal immigrants and drug traffickers often steal items left at campsites.

Hunters must be in good shape and prepared for hot weather and desert survival. Antelope and mule deer also live in the unit, but are not hunted on the refuge. In recent years, both desert sheep hunters had their camps raided by illegal immigrants.