The name of the airport is "Joe Foss Field", so the "F" might stand for Foss. Unless the code predates the naming; I don't know. -- Michael C. Berch mcb@xxxxxxxxxxxxxx On Jul 15, 2004, at 11:56 AM, Blaine Thompson wrote: > Any idea why FSD (Sioux Falls, South Dakota) has that airport code? > > My hunch is FSD = Falls South Dakota, but my hunch has been wrong > before...