S.D. Codified Laws § 31-4-139.1 (2026)
The state trunk highway system includes the following in Pennington County: From a point on U.S. Highway 16 near the east-west quarter line of section twenty-six, township one north, range seven east, thence east and northerly to a point on Interstate Highway 90.
Source: SL 1988, ch 232 ; SL 1994, ch 237 , § 1.