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Devils Tower, Wyoming

Photo: Devils Tower, Wyoming
Known as an igneous intrusion, the 1,267-foot-tall (386-meter-tall) Devils Tower in Wyoming formed when molten rock intruded into the existing rocks. At first the formation wasn't visible, but as wind and water began to erode the sedimentary rock surrounding the tower faster than the harder igneous rock, Devils Tower was born.
Photograph by John G. Wilbanks

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