Adjustable Velcro Back Flagstaff is a city in the U.S. state of Arizona, surrounded by mountains, desert and ponderosa pine forests. It’s a gateway to the San Francisco Peaks, home to Arizona’s tallest mountain (Humphreys Peak) and the Arizona Snowbowl ski resort. Nearby, Wupatki National Monument has Native American pueblo sites, and Walnut Canyon National Monument is dotted with their cliff dwellings.