1965 Map of Hidden Valley

About this map

The Trigo Mountains and Hidden Valley define this arid landscape, which was primarily utilized for military and mining purposes by the mid-1960s. Much of the eastern portion of the map is occupied by the Yuma Proving Ground, an active military installation. Along the mountain slopes, the Black Diamond Mine and Clip Mine point to the area's mineral exploration history. The terrain is deeply carved by numerous ephemeral drainages such as Lopez Wash, Trigo Wash, and Red Cloud Wash, which illustrate the complex watershed of this desert region. A network of Jeep Trails and unnamed Trails provide the only access through the mountain passes, highlighting the remote nature of the territory at the time of the field check.