AdamsShadow
East and West Mitten Buttes rising above Monument Valley. The Mittens form a triangle with Merrick's Butte about 2/3 of a mile to the south and, with Sentinel Mesa, are in the Mitten Buttes Quadrangle.
Monument Valley, a region of the Colorado Plateau characterized by a cluster of vast sandstone buttes, lies within the Navajo Nation Reservation near the Arizona-Utah state line. The valley's vivid red color comes from iron oxide exposed in the weathered siltstone, deposited by the meandering rivers that carved the valley. The darker, blue-gray rocks in the valley get their color from manganese oxide. The buttes are clearly stratified, with three principal layers. The lowest layer is the Organ Rock Shale, the middle is de Chelly Sandstone, and the top layer is the Moenkopi Formation capped by Shinarump Conglomerate.