S.D. Codified Laws § 40-37-13
Whenever the board of directors shall determine to hold a referendum to levy an additional amount as provided in § 40-37-12, the county director of equalization shall mail to each resident livestock owner in that county a ballot stating the amount of additional levy requested, the provisions governing the conduct of the referendum, and the effect of an affirmative result in the referendum. The board of directors shall publish the question in a newspaper not less than two weeks prior to the date the ballots are to be returned. Each resident owner's expression shall be, upon receipt by the county director of equalization multiplied by the number of sheep and cattle determined to be owned in his name and the proposition shall be approved if a majority of the product of such multiplication approves the additional levy. Each ballot must be returned within two weeks and voted to be considered.
SDCL 40-37-13