Monument Valley is a region of the Colorado Plateau characterized by a cluster of vast sandstone buttes, the largest reaching 1000ft above the valley floor. It is located on the Arizona–Utah border, near the Four Corners area. The valley lies within the range of the Navajo Nation Reservation and is accessible from U.S. Highway 163.Monument Valley has been featured in many forms of media since the 1930s. Director John Ford used the location for a number of his best-known films and thus, in the words of critic Keith Phipps, "its 5sqmi have defined what decades of moviegoers think of when they imagine the American West."Geography and geologyThe area is part of the Colorado Plateau. The elevation of the valley floor ranges from 5000to above sea level. The floor is largely siltstone of the Cutler Group, or sand derived from it, deposited by the meandering rivers that carved the valley. The valley's vivid red color comes from iron oxide exposed in the weathered siltstone. The darker, blue-gray rocks in the valley get their color from manganese oxide.
