Below is a list of Gann Valley SD zip codes. For your research we have also included Gann Valley Area Code, Time Zone, UTC and the local Buffalo County FIPS Code. Each Gann Valley South Dakota zip code has a center Longitude / Latitude point (the Gann Valley center is -99.06950378418 / 44.087898254395). For your convenience we have also indicated if that zip code in Gann Valley observes Daylight Savings time.