The Riordan Mansion was built in 1904 for two Riordan families. The mansion is a remarkable example of the Arts and Crafts style of architecture. The house features a rustic exterior of log-slab siding, volcanic stone arches, and hand split wooden shingles. The house has 40 rooms, over 13,000 square feet of living area, and a servant's quarters. The Riordan Mansion was designed by the creator of the Grand Canyon's El Tovar Hotel, Charles Whittlesey. Guided tours of the mansion are offered daily.

The site offers an events calendar, a brief history of the Riordan Mansion, information on children's programs, a photo-gallery featuring 16 photographs of the mansion and its surrounding grounds, and a feature story highlighting one aspect of the park.