Sevier County is a county located in the U.S. state of Utah. It was formed on January 16, 1865, as a split off from Sanpete County to the north. It was named for the nearby Sevier River.[1] Its county seat and largest city is Richfield.[2] As of the 2010 U.S. Census the county's population was 20,802.

The first non-Native Americans to see the Sevier River were most likely the Catholic fathers Silvestre Vélez de Escalante and Francisco Atanasio Domínguez as they passed through on their expedition to California in 1776. The Old Spanish Trail (trade route) was the route they mapped, and over the course of the next hundred years the trail was used by fur trappers, hunters, government officials, and many more. This brought many people through Sevier County. Nearly 100 years later the first colonization began as Richfield, Utah was established within the present day county boundaries. The area was colonized by the Mormon settlers on 15 June 1864. Much of the area was populated by newly immigrated Mormon converts from Scandinavian countries, and because of the growth in this small community they officially created Sevier County in early 1865- From Wikipedia, the free encyclopedia.