DEVILS TOWER
NATIONAL MONUMENT
Wyoming
UNITED STATES DEPARTMENT OF THE INTERIOR, J. A. Krug, Secretary
NATIONAL PARK SERVICE, Newton B. Drury, Director
An 865-foot tower of rock, serving as evidence of volcanic activity that occurred many millions of years ago
Devils Tower National Monument has the distinction of being the first national monument to be created. It was established by proclamation of President Theodore Roosevelt in the year 1906 under authority of the so-called Antiquities Act.
The great natural feature, Devils Tower (known to the Sioux Indian as MATEO TEPEE, meaning Grizzly Bears’ Lodge), is like a huge fluted monumental shaft set upon a mound, alongside the Belle Fourche River and amidst rolling grasslands and pine forests.
The Tower rises to a height of 1,280 feet from the river bed and some 865 feet from its apparent base on the hilltop. The diameter at its base is approximately 1,000 feet, and at the top averages 275 feet. The top surface embraces about an acre and a half, upon which mosses, ferns, grasses, shrubs, and sagebrush grow. Mice, pack rats, and chipmunks have been seen there, and the falcon and hawk make it their home. As viewed from various angles, the Tower has many shapes.
The fresh rock is of a dark grey color which, after weathering, bleaches to a light grey with tinges of buff. Lichens of various colors and shades grow on its face, reflecting tones of light, so that in color its appearance may change several times during the day, depending on conditions of atmosphere and light. On occasion, a red sunset may give it a reddish glow, fading to dull purple.
A Geologic Mystery
As to the mode of origin of the Devils Tower geologists are by no means in agreement. That the rock of the Tower was at one time molten and was forced upward from deep within the earth is no question, and that it cooled beneath the surface is probable. But whether the great shaft as it now stands is in reality hardened lava in the neck of an old volcano the enclosing walls of which have been removed by erosion, or whether it is part of a great sheet or sill of molten rock which was injected between rock layers, cannot be positively stated.
On the basis of either explanation hundreds of feet of rock have obviously been removed by erosion from around the Tower and carried by rivers toward the sea.