Upheaval Dome is a breached domal structure that is surrounded by a well-developed rim syncline; it lies in the rugged canyonlands of southern Utah, near the western margin of the Paradox Basin. Strata that range in age from Permian to Jurassic are exposed in the dome and all have been deformed by the forces which produced the feature; about 3000 feet of Pennsylvanian salt beds underlies the area of the dome. The origin of Upheaval Dome has not been established, but the following hypotheses have been advanced: (1) it is a cryptovolcanic feature; (2) it is a simple salt dome; (3) it was formed by meteorite impact; (4) unloading of overburden through stream erosion resulted in the upward migration of the salt; and (5) it is a salt dome produced by multiple salt movements resulting from local diastrophism and igneous intrusion. The author suggests that the dome is the product of salt flowage resulting from differential pressures which were produced by differential compaction of the sediments over and on the flanks of a buried hill, or monadnock, on the Precambrian basement complex.