Although the Boise Front is encompassed by the natural range of this wide-ranging species, the fact that it only occurs here as small localized populations, restricted to areas where other non-native shrubs have been intentionally planted or escaped, suggests that smooth sumac is only present locally as a result of experimental plantings of a wide diversity of shrubs from throughout the western US, mostly by the Rocky Mountain Research Station in the 1960’s and 1970’s.