S.D. Codified Laws § 31-4-208 (2026)
The state trunk highway system includes the following in Brookings County: From a point on Interstate Highway 29 on the north line of section nineteen, township one hundred nine north, range forty-nine west, thence east to State Highway 13 west of Elkton near the northeast corner of section twenty-one, township one hundred nine north, range forty-eight west.
Source: SL 1984, ch 209 , § 81.