The Gallatin Historical Society, founded in 1977, moved into two rooms in the county jail building in 1979. Built in 1911, the jail was already considered an historic structure. When prisoners were moved to new quarters in January 1982, the county commissioners granted the Society use of the entire building for the Pioneer Museum.

Since 1982, the Pioneer Museum has offered a variety of changing exhibits portraying earlier days in the Gallatin Valley. The Society sponsors various programs throughout the year, including the annual History Conference. The Society is also active with an ambitious outreach program, sending exhibits of photographs and artifacts to fairs, banks, schools, and conferences.