Time in South Dakota 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 * are from
South Dakota Highway 13 intersection with U.S. Route 14 (US 14). SD 13 was formerly a segment of SD 11. This was changed to SD 13 between 1932 and 1935. At that time, its original northern terminus was extended eastward to its current location at US 14 north of Elkton. This was due to a rerouting of US 14 in the early 1930s. South Dakota Highway 13 South Dakota Highway 13 (SD 13) is a state highway in the east-central part of the U.S. state of South Dakota. It connects Flandreau with Elkton. SD 13 was originally part of SD 11's path. SD 13