Devils Tower
Devils Tower is a monolith and popular tourist attraction in the state of Wyoming, rising 1267 feet above the nearby Belle Fourche River, with its summit 5,112 feet above sea level.[1] It was declared America's first national monument by Theodore Roosevelt in 1906.
Devils Tower was formed by molten igneous rock forcing its way into the area's sedimentary rock, cooling before reaching the surface, and the sedimentary rock being eroded away.[2] Scientists have debated for many years exactly what process brought the molten igneous rock up. One early explanation was that it was the remains of a laccolith - a mushroom-shaped underground formation. Another theory is that Devils Tower is the remains of a volcano, though no other evidence of volcanic activity has been found in the area.
The formation's official name contains no apostrophe due to a never-corrected clerical error.[3]