Taken from the Utah Place Names. John W. Van Cott (Links Added)
Wilsonville (Emery) is two and one-half miles southeast of Castle Dale. The families of Sylvester Wilson and his brothers George, Nick, Chris, Davis, and Silas were first to settle in this area.
The following is taken in part from The History of Wilsonville, Utah. Written by Byron J. Wilson (Links Added)
When they settled Wilsonville, Sylvester Wilson was 38 years old.
A mail route was established between Ouray, Colorado and Salina, Utah over the Old Spanish Trail. The route covered 250 miles and took six weeks by horseback. Sylvester contracted to handle mail over this route with a post office established at Wilsonville, the first such stop on the route. He established a rest station with extra horses at Thompson Springs, north of Moab and hired others to carry the mail, one of whom was Selar Cheney who later became his son-in-law. Postal records in Washington D.C. show that the Wilsonville Post Office, with Sylvester as postmaster, was established 26 September 1879 and was discontinued 18 July 1882.