Arizona is a state of extraordinary topographic diversity and beauty. The Colorado Plateau, which covers two-fifths of the state in the north, is an arid upland region characterized by deep canyons, notably the Grand Canyon, a vast gorge more than 200 mi (320 km) long, up to 18 mi (29 km) wide, and more than 1 mi (1.6 km) deep. Also within this region are the Painted Desert and Petrified Forest, as well as Humphreys Peak, the highest point in the state, at 12,633 ft (3,853 m).
The Mogollon Rim separates the northern plateau from a central region of alternating basins and ranges with a general northwest–southeast direction. Ranges in the Mexican Highlands in the southeast include the Chiricahua, Dos Cabezas, and Pinaleno mountains. The Sonora Desert, in the southwest, contains the lowest point in the state, 70 ft (21 m) above sea level, on the Colorado River near Yuma.
The Colorado is the state's major river, flowing southwest from Glen Canyon Dam on the Utah border through the Grand Canyon and westward to Hoover Dam, then turning south to form the border with Nevada and California. Tributaries of the Colorado include the Little Colorado and Gila rivers. Arizona has few natural lakes, but there are several large artificial lakes formed by dams for flood control, irrigation, and power development. These include Lake Mead (shared with Nevada), formed by Hoover Dam; Lake Powell (shared with Utah); Lake Mohave and Lake Havasu (shared with California), formed by David Dam and Parker Dam, respectively; Roosevelt Lake, formed by Theodore Roosevelt Dam; and the San Carlos Lake, created by Coolidge Dam.