@USGS: Browse/download 38,000+ historic photos on our USGS Photographic Library website Long bar with multiplex projectors. Photogrammetry, Topographic Division, U.S. Geological Survey. Denver, Colorado. 1955. Photo credit: USGS Click here to access the site. (Not safe for work unless you are a historian.) Share this: Share on Bluesky (Opens in new window) Bluesky Share on LinkedIn (Opens in new window) LinkedIn Share on Facebook (Opens in new window) Facebook Email a link to a friend (Opens in new window) Email Print (Opens in new window) Print Share on X (Opens in new window) X Like this:Like Loading...