Walnut Canyon National Monument is a United States National Monument located about 10 mi southeast of downtown Flagstaff, Arizona, near Interstate 40. The canyon rim elevation is 6,690 ft; the canyon's floor is 350 ft lower. A 0.9 mi long loop trail descends 185 ft into the canyon passing 25 cliff dwelling rooms constructed by the Sinagua, a pre-Columbian cultural group that lived in Walnut Canyon from about 1100 to 1250 AD. Other contemporary habitations of the Sinagua people are preserved in the nearby Tuzigoot and Montezuma Castle national monuments.