Below is a list of Decker MT zip codes. For your research we have also included Decker Area Code, Time Zone, UTC and the local Big Horn County FIPS Code. Each Decker Montana zip code has a center Longitude / Latitude point (the Decker center is -106.8629989624 / 45.011501312256). For your convenience we have also indicated if that zip code in Decker observes Daylight Savings time.