1956 Map of Mendenhall Springs

About this map

Lake Del Valle State Recreation Area dominates this Alameda County landscape, its reservoir filling the deep canyon of the Arroyo Valle. The 1970s-era revisions, shown in purple, illustrate the transformation of this terrain following the construction of the Del Valle Dam. While much of the area is defined by the high elevations of Crane Ridge and Cedar Mountain Ridge, the map also documents vital infrastructure and early settlements. The Hetch Hetchy Aqueduct tunnels through the northern ridges, crossing beneath Arroyo Mocho near a series of active Mines.