COLORADO PLATEAU

also called Colorado Plateaus, a physiographic province of the Intermontane Plateaus region, extending across the southwestern United States and covering the southeastern half of Utah, extreme western and southwestern Colorado, northwestern New Mexico, and the northern half of Arizona. The province, which occupies about 130,000 square miles (337,000 square km), is bounded by the Rocky Mountains (north and east), the Great Basin (west), and the Sonoran Desert (south). The plateau is dominated by high mountains that are gashed by river canyons or scarred with dry gullies and washes and the beds of intermittent streams. Other topographic features include great shallow basins, sunken deserts, picturesque buttes and mesas, and rare verdant sections of valley. Elevations range from 2,000 feet (600 m) in the Grand Canyon, Arizona, to more than 12,700 feet (3,870 m) in the La Sal Mountains, Utah. Erosion by the Colorado River system has carved deep, brilliantly coloured gorges, notably the Grand Canyon. The province embraces numerous conservation areas and also many Indian reservations. The Colorado Plateau province can be divided into six sections. The highest of these is the High Plateaus of Utah, featuring great rock cliffs and terraces ascending to 11,000 feet (3,353 m) in central Utah. The northernmost section is the Uinta Basin, a dissected plateau abutting the Uinta Mountains in northeastern Utah and northwestern Colorado. South of it is the Canyon Lands, so named because it is a plateau dissected by many deep canyons. It has an indefinite border with the Navajo section, a region with fewer, less deep canyons in Arizona, New Mexico, and small parts of Utah and Colorado. The Grand Canyon section consists of the Grand Canyon and the 7,0009,000-foot (2,1342,743-metre) block plateaus around it. The Datil section is in the province's southeast, in Arizona and New Mexico. It is a land of mesas and valleys and is distinguished by its volcanic features, including lava flows and volcanic necks.