S.D. Codified Laws § 18-7-4.1

Unless specifically required by statute or court rule, a pleading, motion, affidavit, or other document filed with a court of this state, or presented to a judge or judicial officer in support of a request for a court order, warrant, or other relief, is not required to be notarized. Signing a document filed with the court or presented to a judge or judicial officer constitutes an “unsworn declaration", as defined in subdivision 18-7-2(6), without administration of an oath or notarized signature, provided that the signature, as defined by court rules, is affixed immediately below a declaration using substantially the following language: "I declare under penalty of perjury under the law of South Dakota that the foregoing is true and correct". In addition to the signature, the date of signing, the city or other location, and state where the document was signed shall be noted on the document.