Devils Tower is a remarkable geologic feature in Wyoming. It was featured in the movie “Close Encounters of the Third Kind.”
Devils Tower was once the center of a huge molten magma mass that moving up into the surrounding sedimentary rocks of the area. As the magma cooled it formed the column like structures that you see on the sides of the tower. As time went by, all the other softer sedimentary rock around the tower structure weathered away, leaving what we see today.
The rock is called an igneous porphory. The structure of the rocks is called columnar formations. This is a rather common feature in igneous rocks, but Devils Tower is one of the largest formations in the world with this unique column shaped pattern.
Northern Plains tribal lore abounds around this unique natural feature.