Monument Valley is a Navajo Tribal Park. Before the Navajo, the Anasazi Indians lived here. There are beautiful petroglyphs created by the Anasazi throughout the park.
This area was once covered by ocean. When the water receded, it left behind deposits of siltstone and shale. Years later, the Colorado plateau was pushed upward due to pressure from beneath. The landscape has been breaking, cracking and eroding ever since.
The base of the monuments are composed of Organ Rock shale, the middle layer is vertically jointed de Chelly sandstone and the top layer is Moenkopi shale and Shinarump siltstone.
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