1972 Map of Otay Mountain

About this map

The San Ysidro Mountains dominate this rugged Southern California landscape, where the international boundary between the United States and Mexico cuts across the southern terrain. This 1970s survey captures a transition point between the upland slopes of Otay Mountain and the remote drainage systems of Cottonwood Creek and the Tijuana River. Traces of early 20th-century industry and infrastructure are preserved in the presence of the Donohoe Mine and several gaging stations along the creek beds, while the Dulzura Community Center serves as a small anchor for the sparse local population. The map's network of unpaved routes, such as the Minnewawa Truck Trail and the Otay Mtn Truck Trail, reveals a landscape managed for fire access and telecommunications, evidenced by the clusters of Radio Towers at high elevations. Water sources like Echo Spring and Lupe Spring are vital markers in this arid region, providing historical context for early ranching and mining operations in Marron Valley.