The Mogollon Rim is a prominant escarpment that curves across Arizona from the western end of the Grand Canyon to southwest New Mexico. More than 200 miles long, this wall of late-Paleozoic sediments, broken by numerous canyons, represents the south-western edge of the Colorado Plateau. Its upper surface of Permian Coconino Sandstone rises 7000 to 9000 feet above sea level; the highest areas are near the Arizona-New Mexico border. Sedona and Payson sit near the base of the Mogollon escarpment while Williams, Flagstaff, Holbrook and Winslow are atop the plateau, some 6000 feet higher (and two life zones colder) than Phoenix.
South of this spectacular Rim, the land falls away as a network of mountain ranges and foothills, molded and drained by the Verde, Salt and Gila Rivers, which merge in the low desert of Greater Phoenix. The surface of the Colorado Plateau is covered with vast tracts of ponderosa pine, dotted with Tertiary volcanic peaks and incised by the deep canyons of the Colorado and Little Colorado Rivers. Forests of ponderosa pine cover higher elevations of the mountains south of the plateau while pinyon-pine woodlands adorn the lower slopes. At elevations near 3000 feet, saguaro cacti grace the scene, distinctive figures of the Sonoran Desert landscape.
