S.D. Codified Laws § 9-14-16
No mayor, alderman, commissioner, or trustee may hold any other office under the municipality while an incumbent of such office. The term "office" does not include membership on any municipality board, if the ordinance or resolution establishing the board specifically includes the mayor, an alderman, commissioner, or trustee in the membership of the board. No mayor, alderman, commissioner, or trustee is disqualified from holding such office in any municipality as a result of holding any liquor license or being the spouse of a person holding any liquor license. No mayor, alderman, commissioner, or trustee who is the holder of a liquor license may vote on the issuance or transfer of any such license. No auditor or clerk may hold the office of treasurer under the municipality while an incumbent of such office.
SDCL 9-14-16