S.D. Codified Laws § 32-22-9
Combination of vehicles of more than two units--Violation as misdemeanor
Except as provided by §§ 32-19-8 , 32-22-8.1 , 32-22-10 , 32-22-11 , 32-22-12.1 , and 32-22-12.2 , any combination of vehicles consisting of more than two units, including a truck, tractor, or towing vehicle, may not operate on a public highway. A violation of this section is a Class 2 misdemeanor.
Source: SDC 1939, § 44.0336 (2) (d) as added by SL 1947, ch 192; SL 1955, ch 173; SL 1959, ch 260, § 1; SL 1963, ch 258, § 2; SL 1964, ch 124; SL 1981, ch 245, § 1; SL 1982, ch 243, § 1; SL 1982, ch 244, § 1; SL 1984, ch 230, § 12; SL 1989, ch 264, § 17; SL 1997, ch 193, § 2.