The Colorado Plateau, a series of flat lands, gorges, mountains and valleys, extends south into Arizona, and covers most of northern half of the state. The Black Mesa, Painted Desert, and Monument Valley in northeastern Arizona are some of the plateau's most interesting areas. Scattered tree-covered ranges of the Rocky Mountains wind through the Plateau, including the Black, San Francisco and White Mountains. Humphreys Peak is the highest point at 12,633 ft.