Devil’s Tower was declared the first national monument in the United States by president Teddy Roosevelt back in 1906. It is comprised of igneous rock in an area which is otherwise sedimentary rock. There are several theories as to how the tower was formed, many believing that it is all that remains of an ancient volcano. You might remember it for its role in the 1977 movie Close Encounters of the Third Kind. I’ve been to the monument several times — this photo being taken on my most recent visit, late in the day, as the last rays of the sun illuminated the western face of the rock.
Nikon D700 with Nikkor 17-35mm lens (at 17mm) ISO 200, f/18 at several shutter speeds (HDR image)