S.D. Codified Laws § 9-10-6
Within sixty days after an election directing the employment of a manager in any commission-governed municipality, a special election shall be called and held to elect the nine commissioners. A plurality vote in the election of commissioners is sufficient to elect the commissioners.
The commissioners shall qualify as provided by law and organize by electing a commissioner to act as mayor until the first regular meeting of the board in the month following the first annual election of commissioners. At the first regular meeting in the month following the annual election, the commissioners shall elect a commissioner to act as mayor for a term of one year.
The board has the same powers conferred upon the board of commissioners in a commission-governed municipality pursuant to chapter 9-9. Except as otherwise provided in this chapter, the board shall be governed by the provisions of the law relating to a commission-governed municipality.
SDCL 9-10-6