Look what we recently found in the Idaho State Historical Society Archives: https://idahohistory.contentdm.oclc.org/digital/collection/p16281coll21/id/187/rec/1
It is a beautiful map of airports, including the Contract Air Mail Routes, in 1934. You can use it to see where the beacons used to be and you will find that some of them are still in place (and a few moved to new locations). You will also find some arrows remaining. We are working hard to restore this aviation heritage and teach people about the importance of Idaho in the history of commercial aviation.