McMillan played an important part in the development of Flagstaff. When Coconino County was formed in 1891, he was elected chairman of the Board of Supervisors and helped the county through its formative period. He was the first postmaster and was a member of the first library board. In 1888 he bought the shell of the building on the northwest corner of Leroux St. and Route 66, begun by others in 1887, and completed it. His first tenants were a bank and a hotel (the Bank Hotel). In 1892 the hotel became the terminus for the Flagstaff-Grand Canyon Stagecoach. The McMillan Opera House, located on the ground floor, became the premiere place in town to host plays, dances, and other events. (Courtesy: Rio de Flag History website)

