Imagine flying high above the Rocky Mountains in late 1939, looking downwards towards the peaks below. Now picture yourself staring down at the city of Denver around the same time, peering onto the tops of residential buildings, factories, and feedlots. Until time travel is feasible, this probably isn’t possible for most of us. Of course, for those with a penchant for the past, aerial photographs...

From 1938 to 1947, the United States Forest Service took thousands of aerial photographs of the state of Colorado. The hope was that these images would be used by agronomists, land use planners, farmers, and other groups with a vested interest in these lands. Today, 1,700 of these images are part of the University of Colorado's Digital Collections. Visitors can search for available images by using...