Montana Airways

In the early 1920s, the War Department had requested that the United States Lighthouse Service (USLHS) help develop beacons that would shine skyward for use as guideposts by pilots, who had at that time only their compasses and visual skills for navigation. Pilots had been using lighthouses as markers since the earliest days of aviation. The Lighthouse Service was already equipped with structures, beacons, and a system of districts that could, it was hoped, easily and with minimal expense be adapted to provide more effective navigational landmarks for pilots.