Hoooos are tall thin spires of rock that protrude from the bottom of arid basins and badlands. They are composed of soft sedimentary rock and are topped by a piece of harder, less easily-eroded stone that protects the column from the elements. They are mainly located in the desert in dry, hot areas. In common usage, the difference between hoodoos and pinnacles or spires is that hoodoos have a variable thickness often described as having a "totem pole-shaped body." A spire, on the other hand, has a smoother profile or uniform thickness that tapers from the ground upward. (Geology purists do note that only a tall formation should be called a hoodoo; any other shape is called a 'hoodoo rock'.) Hoodoos are most commonly found in the High Plateaus region of the Colorado Plateau and in the Badlands regions of the Northern Great Plains (both in North America). While hoodoos are scattered throughout these areas, nowhere in the world are they as abundant as in the northern section of Bryce Canyon National Park. WED Enterprises (now Walt Disney Imagineering) notably based the design of the Disneyland version of the popular Big Thunder Mountain Railroad around a series of hoodoos, although these were constructed out of steel and concrete.