Completed in 1900 at a cost of approximately $136,000, this building was designed by James Riley Gordon of San Antonio, Texas, and served as the first Arizona-owned seat of government during the late territorial days and the transition to statehood in 1912. The original structure is 184 feet long and 84 feet deep. Its exterior is constructed entirely of Arizona products, including grey granite from the Salt River Mountains, tufa from Yavapai County, and a foundation of malapia rock from Camelback Mountain.