Tertiary volcanic and intrusive rocks underlie a large area surrounding Marysvale in southwestern Utah. Part of the Beaver quadrangle and four complete 15-minute quadrangles, Marysvale, Delano Peak, Sevier, and Monroe, have been mapped to cover the areal extent of these rocks. Mapping in the Beaver quadrangle has been restricted to the northeastern part, the area containing the western part of this volcanic province.
The mapped area of the quadrangle contains the westernmost slopes of the Tushar Mountains, which slopes steeply to the eastern edge of the Great Basin. The area is thoroughly dissected and its topography is extremely rugged, having a maximum relief of more than 3,500 feet. Wildcat, Indian, and North Creeks have developed the most prominent and steeply walled canyons.
The area of about 42 square miles lies about 6 miles northeast of Beaver. A main nortb-south thoroughfare, United States Highway 91, connects Beaver with Salt Lake City 208 miles to the north. Roads in the canyons of Indian Creek and North Creek allow entry into the area.
The geology of the Beaver quadrangle was mapped by Callaghan, but most of the report was written by Parker from field notes, previous reports, and oral data supplied by Callaghan.
