Below is a list of Greycliff MT zip codes. For your research we have also included Greycliff Area Code, Time Zone, UTC and the local Sweet Grass County FIPS Code. Each Greycliff Montana zip code has a center Longitude / Latitude point (the Greycliff center is -109.79000091553 / 45.765800476074). For your convenience we have also indicated if that zip code in Greycliff observes Daylight Savings time.