Flat-topped hills, which occur primarily in the southwestern area of the United States, are sometimes called buttes, mesas or plateaus. The name used depends largely on the size of the hill in question.
Small and isolated flat-topped hills are generally referred to as buttes. The Coyote Buttes of Utah's Grand Staircase-Escalante National Monument are prime examples. Mesas are typically larger in area as with the Grand Mesa in western Colorado. Plateaus are the largest in area of the various kinds of flat-topped hills. Their top areas can cover vast areas, such as the Colorado Plateau, with an area of over 130,000 square miles spread out over four states in the U.S. Southwest.