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 168 maintained by SDDOT. In 2012, the traffic on the highway was measured in average annual daily traffic. The route had an average of 165 vehicles. The designation is not a part of the National Highway System, a system of highways important to the nation's defense, economy, and mobility. The Unofficial South Dakota Highways Page South Dakota Highway 168 South Dakota Highway 168 (SD 168) is a state highway in Butte County in the U.S. state of South Dakota. It runs from U.S. Route 85 (US 85) to SD 79. The highway is maintained by the South Dakota Department of Transportation