http://www.zipinfo.com/cgi-local/zipsrch.exe?cnty=cnty&zip=95385&Go=Go ZIP Code Lookup] The first post office in the area opened under the name of San Joaquin in 1851; that post office closed in 1852, reopened in 1874, and was moved 3 miles southwest in 1888, after which its name was changed to Vernalis.