1974 Map of Santiago Peak

About this map

Santiago Peak dominates this 1974 orthophotoquad, which utilizes aerial imagery to document the Santa Ana Mountains before extensive late-twentieth-century development altered the surrounding Orange County landscape. The photographic detail reveals the complex network of ridgelines and drainage basins defined by Silverado Canyon to the north and Trabuco Canyon further south. Produced through collaboration between the Orange County Board of Supervisors and federal surveyors, this study provides a precise visual record of natural landforms and early access roads. The transition from the high summit down to the lower alluvial fans demonstrates the geological character of the region as it existed just before the rapid suburban expansion of the 1970s and 1980s, preserving the state of these canyons at a specific moment in California's land-use history.