The first route to use the number 150 was established in the 1920s, when it connected SH 17 at Mosca to SH 69 at Gardner over Mosca Pass which is no longer maintained for automobile travel. The route was deleted by 1954 and resurrected in 1960, when it connected Mosca with the Great Sand Dunes National Park. This routing was deleted in 1973 and resurrected again to its current routing today the following year.