The San Simon Valley is a broad valley east of the Chiricahua Mountains, in the northeast corner of Cochise County, Arizona and southeastern Graham County, with a small portion near Antelope Pass in Hidalgo County of southwestern New Mexico. The valley trends generally north-south but in its northern portion trends northwest-southeast. The San Simon Valley separates the Chiricahua Mountains, Dos Cabezas Mountains and Pinaleno Mountains on the west from the Peloncillo Mountains and the smaller Whitlock Mountains to the east.