The magnificent American monument with mysterious origins.
Among the pine forests of Crook County, Wyoming, stands an enormous lump of rock reaching high up into the sky. Known as Devils Tower, it is so awe-inspiring that in 1906, President Theodore Roosevelt established it as the United States’ first national monument, but no one quite knows how it formed.
What we do know is that it is made from phonolite porphyry, an igneous rock that is formed when magma cools and crystallises. In this case, as the magma cooled, it also contracted, cracking the rock into the polygonal columns that now make up the Tower. Most geologists agree that the rock formed when magma rose up into the surrounding sedimentary rock, but there are three possible theories for how this happened.
The formation theories:
Did you know? Devils Tower is officially missing an apostrophe, as it was omitted in a proclamation signed by Roosevelt.
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