The Sevier River drains a 5,500-square-mile portion of the mountainous transition zone between the eastern border of the Great Basin and the Colorado Plateau. The Sevier flows about 240 miles north from Garfield County through desert lands before it bends west and then south to empty into the mostly dry bed of Sevier Lake in West Millard County at the end of its 325-mile length.

During historic times, the Native Americans known as Paiutes and Goshutes have occupied the drainage. When the Dominguez-Escalante party came through the area in 1776, they reported the natives to be more Spanish than Indian because of their beards. The explorers' cartographer, Don Bernardo de Miera, named Sevier Lake after himself and called the river Rio Buenaventura, the "river of the good journey." The Sevier takes its name from an appellation by the Spanish trappers Moricio Arce and Lagos Garcia, who came from Taos in 1813 to trade with the Utes around Utah Lake. Escaping south after troubles with the Utes, they said they traveled to the "Rio Sebero" (also reported as Severo or Seviro--Spanish for "severe" or "violent"). Trapping was popular in the region until about 1830. The river is on the California leg of the old Spanish Trail, a trade route which joined Santa Fe to the west coast; it arched north into the Great Basin to avoid the impassable barrier of the lower Colorado River.

Settlement of Utah territory by whites began in 1847 and led to colonies in the region both north and south. In 1850 Mormon settlers were sent by Brigham Young to the Sevier River Valley. Native Americans in the area felt threatened when settlement encroached, and an altercation between settlers and Indians in 1852 left four Indians dead in Salina. At the same time, coming west through Salina Canyon on a railroad route survey was a government party led by John W. Gunnison. The surveyors were caught in an early morning ambush by vengeful Indians, who killed Gunnison and six of his crew.

Irrigation near the mouth of the river started with settlement in 1859 in west Millard County. Obtaining water for irrigation was the most significant challenge for settlers in the semi-arid land. Uncontrolled flooding caused downstream irrigators to abandon many dams before they were finally permanently established in 1912.

After floods, upriver diversions were the next most vexing challenge. The Higgins Decree of 1900 divided the waters of the lower Sevier at Vermilion Dam and established a commission to adjudicate user rights. Other decisions followed until 1936, at which time the Cox Decree finally allotted all the water of the Sevier River. It is one of the most used rivers in the United States. Less than 1 percent, or 44,840 acre-feet, of the total precipitation is not consumed. Consumption is about 1,100,000 acre-feet annually.