Simpson Springs, a dependable water source in southeastern Tooele County, became a vital stop on Utah’s desert crossing because it lay in an otherwise dry region. Likely used by Native Americans long before Euro-American routes arrived, it was first called Egan Spring and later renamed for Captain James H. Simpson, whose 1858 survey helped establish a military mail route to California. The site served the Overland Mail, Pony Express, Overland Stage, and Wells Fargo as a key watering and relay point. Its transportation role declined after the Transcontinental Railroad in 1869, but it later saw Civilian Conservation Corps and World War II military use.