1956 Map of New Idria

About this map

New Idria (Idria PO) serves as the primary hub for this mid-century look at the Diablo Range, where the landscape is defined by extensive mining operations and remote cattle ranching. The map details a complex industrial network of quicksilver and mineral extraction, featuring sites like the Molina Mine, Alpine Mine, and Santa Rita Mine scattered across the high ridges. This 1956 field-checked data captures the transition between the San Benito and Fresno County lines, revealing how human settlement followed the geology of the San Benito River and Clear Creek. Significant terrain features such as San Benito Mtn and Joaquin Ridge dominate the topography, while isolated landmarks like Ashurst Ranch and the El Rancho Cantua provide evidence of long-established land use in the Vallecitos region. The presence of a Landing Strip near the ranching areas highlights the isolation of these interior mountains, where access often relied on small aircraft or unpaved roads.