S.D. Codified Laws § 25-4-14

If one party deserts the other and, before the expiration of the statutory period required to make the desertion a cause of divorce, returns and offers in good faith to fulfill the marriage contract and solicits condonation, the desertion is cured. If the other party refuses such offer and condonation, the refusal shall be deemed and treated as desertion by such party from the time of the refusal.