1959 Map of Collins Valley

About this map

Anza - Borrego Desert State Park dominates this mid-century landscape where the Riverside and San Diego county line traverses arid canyons and steep ridges. The survey illustrates a terrain defined by seasonal drainage and isolated springs, centered on the broad expanse of Collins Valley. The Anza Trail and various Jeep Trails provide the primary access through this remote environment, connecting small riparian oases like Middle Willows and Lower Willows. To the north, the Santa Rosa Mts rise sharply, dissected by Alder Canyon and Nicholas Canyon. The presence of numerous bench marks and vertical angle bench marks, such as Vabm 3433 and Vabm 1837, indicates the detailed topographic work required to map this complex system of alluvial fans and rocky outcrops, including the prominent Monkey Hill and the desolate Jackass Flat.