2010 South Dakota Code
Title 31 - HIGHWAYS AND BRIDGES
Chapter 04 - State Trunk Highway System
Section 31-4-141 - U.S. Highway 18 from Wyoming to Iowa.

31-4-141. U.S. Highway 18 from Wyoming to Iowa. The state trunk highway system includes the following in Fall River, Shannon, Bennett, Todd, Tripp, Gregory, Charles Mix, Douglas, Hutchinson, Turner, and Lincoln counties:
(1) From a point on the Wyoming state line near the northwest corner of section six, township nine south, range one east, thence easterly via Edgemont, Hot Springs, Martin, Mission, Winner, Colome, Gregory, Burke, Bonesteel, Lake Andes, Ravinia, Olivet, Menno, and Davis to Interstate Highway 29 southwest of Canton near the north line of section six, township ninety-seven north, range fifty west;
(2) From a point on Interstate Highway 29 west of Canton near the north line of section nineteen, township ninety-eight north, range fifty west, thence east via Canton to the Iowa state line east of Canton in the southwest quarter of section sixteen, township ninety-eight north, range forty-eight west.

Source: SL 1984, ch 209, § 14.