I grew up in Arizona and visited the Painted Desert many times. There is a large area on both the Navajo and the Hopi indian reservations which is loosely called "The Painted Desert". I would suggest planning for several days and visiting the Petrified Forest. Leave from Flagstaff, drive to Tuba City then across to Chinle and come back to Flagstaff by way of Interstate 10. If you have time, be sure and visit Oak Creek Canyon, Sedona and Montezuma's Castle south of Flagstaff also. Beautiful sights and unique scenery. Nice people there too. Have fun.