is rapid city sd mountain time?
South Dakota east part is in the Central Time Zone, and its west part is in the Moutain Time Zone. Cities in Central Standard Time Zone include Brookings, Watertown, Sioux Falls, Vermillion, Huron, Mitchell, Aberdeen, Pierre, Chamberlain, Madison and Mobridge. Cities in Moutain Standard Time Zone include Rapid City and Spearfish. Daylight Saving Times are used in Noth Dakota time zones during summer. Currently the east part observes Central Daylight Time, the west part observes Mountain Daylight Time. South Dakota Time Zones Map.