South Dakota Codified Laws — Title 10 (Taxation)
SDCL § 10-3-3 — Appointment of county director--Mayor participating
The county director of equalization shall be appointed by the board of county commissioners at either a special or regular meeting of the commissioners. If a single municipality contains fifty percent or more of the population of a county, the mayor of the municipality and the board of county commissioners shall make the appointment, and the mayor is entitled to sit and vote with the board.
Source: official text