Older style cut-out US highway sign. This sign appears to be from the late 1940's or early 50's in that is uses crushed-glass reflective sheeting (Photo by Joe Koehler).
Current style Montana state route marker. This sign has an "Intstalled 1981" sticker on back. (My collection)
Miles City, MT. 1950's era state route marker still on the pole in 1979. This is a flat reflective version of the sign below. (Photo by Michael Summa)
Original Montana state route sign. This style was used from the 1920's to the 40's. Route 6 later became US-12. This sign is embossed and non-reflective. (Collection of Robert Edgar)