Starting off as middle-class, second-generation Irish immigrants, the Riordans amassed a fortune in the lumber industry in Flagstaff, Arizona. The eldest brother, Denis “Matthew” Riordan, became the foreman of the Ayer Lumber Mill in 1884. In 1887, Matthew bought the mill, then invited his brothers Timothy and Michael to work alongside him. Matthew sold the renamed Arizona Lumber and Timber Company to his brothers in 1897. By 1903, Timothy and Michael earned enough money to build the Riordan Mansion. Tim married Caroline Metz in 1889, and Michael married her sister Elizabeth in 1892. Timothy and Michael moved into the mansion with their wives and kids in 1904, but descendants of the family lived in the home until the 1980s. The Riordan family contributed to the Flagstaff community in education, banking, business, water development, and conservation.
Riordan Mansion is a 13,000-square-foot duplex-style mansion. Construction only took nine months. Timothy and his family lived in the east side, and Michael and his family lived in the west. The floor plans of both sides are near perfect mirror images of each other, though there are a few stylistic differences. The center room is shared by both sides of the family. Charles Whittlesey designed the mansion in the Arts & Crafts architectural style – promoting local materials, built-in furniture, and the celebration of nature. The walls are lathe and plaster with slab siding to give the appearance of a log cabin. The wood is local Ponderosa Pine, while volcanic rock makes up the base. Whittlesey designed built-in ice boxes, closets, window seating, countertops, and other surfaces throughout the house. The duplex contains one of the largest public collections of Stickley furniture, including some from Harvey Ellis.
Arizona State Parks and Trails (ASPT) owns Riordan Mansion. Bob Chambers, the son-in-law of Timothy, donated the east half of the home in 1981. Blanche, the oldest daughter of Michael, donated the west half of the home in 1985. After the 2008 recession, ASPT nearly closed the mansion. Due to the efforts of volunteers and a partnership with the Arizona Historical Society, Riordan Mansion remained open.
Staff and volunteers offer hour-long tours throughout the day year-round, though they are closed Tuesdays and Wednesdays during the winter. Guided tours take visitors room by room through Tim’s side of the home, giving the history of the family and of Flagstaff and showing much of the original furniture. Michael’s side is open as a museum with interpretive displays for guests to explore at their leisure. Tours cost $10 per person, though visitors can take complimentary walks around the grounds and look at exhibits in the Visitor Center. With five acres of land, Riordan Mansion can provide the perfect spot for a wedding or a picnic.