Sevier County is located in the high plateau country of central Utah. Most of the towns lie near the Sevier River in a fertile valley bordered on the west by the Pahvant Range and on the east by the Wasatch and Fish Lake plateaus.
National forests cover almost half of the county.
The area is seismically active, and a number of earthquakes have centered in the southern part of the county on the Sevier Fault. Many prehistoric Indian sites have been found. Sudden Shelter, an Archaic site on Ivie Creek, contains the oldest time record in Utah east of the Wasatch B.C. 5080 to A.D. 1900. Fremont and Sevier Culture sites continue to be found, especially during construction projects. Fremont State Park preserves a recently uncovered Fremont Culture prehistoric village.