Time in South Dakota the zone.tab. Time in South Dakota South Dakota lies in both the Mountain Time Zone and the Central Time Zone. Mountain Time roughly contains the western half of the state, but not all of it. Rapid City is the largest city in the Mountain Time portion of the state. Central Time contains the eastern half of the state and roughly more of the state than the Mountain Time Zone and includes the state capital Pierre and the largest city, Sioux Falls. The 2 zones for South Dakota as given by zone.tab of the IANA time zone database. Columns marked *
South Dakota Highway 123 South Dakota Highway 123 South Dakota Highway 123 (SD 123) is a state highway in the U.S. state of South Dakota that runs from U.S. Route 12 (US 12) near Marvin to SD 15 in Wilmot. It is maintained by the South Dakota Department of Transportation (SDDOT), and is not part of the National Highway System. SD 123 begins at an intersection with US 12 east of Marvin in Grant County and begins north through open plains. The highway enters Roberts County north of its southern terminus and continues north through rolling farmland. North of the county line, the route