S.D. Codified Laws § 46A-4-89
The board of directors may reject any bids that are not, in the judgment of the board, a fair and just consideration for the property. After bids are thus rejected by the board, the board may by private negotiations with any person sell and convey by deed, executed by the board, all of the property for part cash and part in deferred payments, bearing the same interest as the bonded indebtedness of the district. If the district has no bonded indebtedness, the interest upon the deferred payments shall be as agreed upon by the board and the purchaser, not exceeding the rate allowed by law. The deferred payments are a lien upon all the property thus sold by the board and have the same force and effect as a mortgage against the property and may, when due, be foreclosed in the manner provided by law for the foreclosure of mortgages.
SDCL 46A-4-89