1975 Map of Harrison Mtn.

About this map

The northern reaches of San Bernardino meet the rising slopes of the San Bernardino Mountains in this mid-1970s orthophotoquad. Produced by the U.S. Geological Survey in cooperation with the Soil Conservation Service, this map utilizes aerial imagery from September 1975 to document the distinct boundary between urban development and the steep, undeveloped terrain of the Harrison Mtn. region. While the lower southwestern corner shows a structured grid of residential streets and industrial plots, the remainder of the landscape is dominated by complex drainages and fire breaks that traverse the ridges. This photographic record captures a specific moment in the growth of Southern California, showing where the expansion of the city begins to negotiate with the natural geography of the Transverse Ranges.