1940 Map of Dome Rock Mts

About this map

Mining operations and rugged desert topography define this 1933 survey of the Arizona-California borderlands. The Dome Rock Mountains dominate the center of the sheet, where a network of prospector sites like the Copper Bottom Mine, Cinnabar Mine, and Colvic Mine underscore the region's hard-rock extraction history. To the west, the Colorado River serves as the dividing line between Riverside County, California and Yuma County, Arizona, with the Colorado River Indian Reservation Boundary cutting across the mountain flanks. The map illustrates a desert drainage system where dry beds like Seventy Mile Wash and Goodman Wash lead toward the river valley. Key transit routes through the massif are documented via Diablo Pass and Marquetta Pass, revealing how travelers and miners navigated this arid landscape before modern infrastructure.