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 73 South Dakota Highway 73 South Dakota Highway 73 (SD 73) is a state route that runs across western South Dakota. It begins at the Nebraska border north of Merriman, Nebraska, as a continuation of Nebraska Highway 61. It runs to the North Dakota border, where it continues as North Dakota Highway 49. It is just more than in length. When designated in the 1920s, South Dakota 73 only consisted of the segment from Faith (U.S. Route 212) to Lemmon (U.S. Route 12). The remainder of the route was unnumbered. Around 1935, SD 73 was extended south from Faith, absorbing what