Four stories with two-story wings, Berthoud Hall, built as a WPA project, houses the Geological Museum, whose treasures include six murals by Irwin D. Hoffman depicting the history of mining from prehistoric times. Hoffman painted the series for the 1939 Golden Gate Exposition in San Francisco. This yellow brick edifice is lavishly trimmed in terracotta with exuberant Beaux-Arts detailing bordering on the rococo for extravagant entry surrounds, pilasters, spandrels, and wide, double-bracketed eaves.