Monument Valley by Navajo known as Tsé Biiʼ Ndzisgaii, meaning valley of the rocks is a region of the Colorado Plateau characterized by a cluster of vast sandstone buttes, the largest reaching 1,000 ft above the valley floor. Monument Valley is located on the northern border of Arizona with southern Utah and lies within the range of the Navajo Nation Reservation. The floor is largely Cutler Red siltstone or its sand 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. The buttes are clearly stratified, with three principal layers. The lowest layer is Organ Rock shale, the middle de Chelly sandstone and the top layer is Moenkopi shale capped by Shinarump siltstone. Pictured here John Ford’s Point offers an excellent view of the valley. While there a dapper Navajo man in a red shirt astride a well-groomed black horse rode out onto the point. I hear he does this daily, but seeing him out on the point alone, with the majesty of the valley behind him was a huge thrill for me.