S.D. Codified Laws § 31-4-168 (2026)
The state trunk highway system includes the following in Union County: From a point on Interstate Highway 29 northwest of Elk Point near the north quarter corner of section thirty, township ninety-three north, range fifty west, thence easterly to the Iowa state line near the southwest corner of section thirty, township ninety-three north, range forty-eight west.
Source: SL 1984, ch 209 , § 41.