 Sheffield is located at the intersection of State Highway 290, State Highway 349, and FM 1217 on the eastern edge of Pecos County, approximately 16 miles southeast of Iraan and 60 miles east of Fort Stockton in eastern Pecos County.The first documented Europeans to visit the area were Spanish explorer Gaspar Castaño de Sosa and his men, who traveled up the Pecos River in 1590.Although several Spanish-led expeditions followed, no permanent settlements were established in the area.