1959 Map of Briones Valley

About this map

The rugged ridges and deep canyons of Contra Costa County define this 1959 landscape, captured just before the rapid suburban expansion shown in later purple revisions. High elevations like Grizzly Peak and Vollmer Pk overlook a series of massive water projects, most notably the San Pablo Reservoir and the Lafayette Reservoir. These reservoirs, managed by the State of California Department of Water Resources, underscore the critical infrastructure development of the mid-20th century.