Photograph of airmail hanger at Rock Springs, Wyoming

c. 1920

The Rock Springs, Wyoming airmail field was a main stop on the Post Office Department's 2,680-mile-long transcontinental airmail flyway, positioned between airmail fields located at Salt Lake City, Utah and Rawlins, Wyoming. The western portion of the flyway was the last to become operational, with full transcontinental airmail service beginning on September 8, 1920. According to the 1921 "Transcontinental Air Mail Pilot's Log of Distances, Landmarks, and Flying Directions" provided to all airmail employees, the Rock Springs facility was described as: "The field is in the valley at the foot of Pilot Butte about 4 miles from Rock Springs. It is triangular in shape, the hangar being located in the apex. The surface of the field is good. The best approach is from the eastern side."