Aspen's factory-like armory, built in three months, hosted military drills by day and balls, festivals, and concerts at night. It served as an auditorium, gymnasium, Odd Fellows Hall, and roller rink before becoming City Hall in 1957. A soft red brick building trimmed in Peach Blow sandstone, it has a gable roof of corrugated sheet metal with hipped dormers. The second-story hall and first-floor storefronts have been carved up into three stories of small offices for city officials.