S.D. Codified Laws § 62-1-3

As used in this title, the term,employee, means any person, including a minor, in the services of another under any contract of employment, express or implied, (and including as to a deceased employee, the employee's personal representative, dependents, and other persons to whom compensation may be payable), except:

(1) Any person whose employment is not in the usual course of the trade, business, occupation, or profession of the employer;

(2) Any official of the state or of any subdivision of government elected or appointed for a regular term of office or to complete the unexpired portion of any such term. However, the governing body of any subdivision may elect to treat officials of the subdivision as employees for the purposes of this section.

Any employer performing labor incidental to the employer's occupation who has elected to proceed under the provisions of § 58-20-3 by purchasing workers' compensation insurance to cover himself or herself, may be deemed to be an employee under this section. However, nothing in this section may be construed as to affect that person's rights as an employer for purposes of §§ 62-3-1 and 62-3-2 .

Source: SL 1917, ch 376, §§ 8, 55; RC 1919, §§ 9443, 9490; SL 1929, ch 253; SDC 1939, § 64.0102 (2); SL 1943, ch 313; SL 1949, ch 441; SL 1951, ch 467; SL 1957, ch 493; SL 1959, ch 454; SL 1966, ch 262; SL 1975, ch 322, § 2; SL 2008, ch 278, § 1.