The Colorado Plateau is a physiographic region of SW North America, c.150,000 sq mi in Arizona, Utah, Colorado, and New Mexico. It's characterized by broad plateaus, ancient volcanic mountains ranging from 5,000 to 13,000 ft (1,5203,960 m), and deeply dissected canyons lined with often brightly colored sedimentary and volcanic rocks. About 90% of the area is drained by the Colorado River and its main tributaries: the Green, San Juan, and Little Colorado. Much of the Plateau's landscape is related, in both appearance and geologic history, to the Grand Canyon. The plateau generally rises east-west. Zion National Park is located along the plateau's western edge. These rock layers have been uplifted, tilted, and eroded, forming a feature called the Grand Staircase, a series of colorful cliffs stretching between Bryce Canyon and the Grand Canyon. The bottom layer of rock at Bryce Canyon is the top layer at Zion, and the bottom layer at Zion is the top layer at the Grand Canyon.
Confluence of the Green River and Colorado River in Canyonlands National Park