S.D. Codified Laws § 46A-7-34

The lien for the bonds of any series may be on a parity with or a preferred lien to that of any subsequent series, and the lien for the payments due to the United States under any contract between the district and the United States, accompanying which bonds have not been deposited with the United States, may be a preferred lien to that of any issue of bonds or any series of any issue subsequent to the date of such contract.