S.D. Codified Laws § 15-6-44.1

A party who intends to raise an issue concerning the law of a foreign country shall give notice in his pleadings or other reasonable written notice. The court, in determining foreign law, may consider any relevant material or source, including testimony, whether or not submitted by a party or admissible under § 15-6-43. The court's determination shall be treated as a ruling on a question of law.