1974 Map of Black Star Canyon

About this map

The Santa Ana Mountains dominate this 1974 orthophotoquad, showing the intricate network of ridges and canyons before significant modern development reached this part of the range. This aerial perspective, captured by the Geological Survey in cooperation with the Orange County Board of Supervisors, reveals the raw geography of the Santiago Reservoir and the winding course of the Santa Ana River along the northern edge. The orthophoto format provides a unique visual record of the land surface, illustrating the contrast between the steep, brush-covered slopes and the relatively undeveloped alluvial flats of the day. It captures a moment in the mid-1970s when much of this rugged landscape remained in its natural state, providing an essential reference for understanding the historical topography of the canyon country before urban expansion altered the surrounding valleys.