Yellowstone Bank celebrated its centennial in 2007, and continues to practice a community-oriented approach to banking. B.M. Harris founded Yellowstone Bank in 1907 in Park City. The bank is still controlled and operated by the fourth generation of the Harris family. With nearly $700 million in assets, Yellowstone Bank now has branches in Absarokee, Columbus, Billings, Bozeman, Laurel and Sidney.