S.D. Codified Laws § 25-2-13
Current with legislation signed by the governor on or before 3/6/2024
A husband and wife cannot by any contract with each other alter their legal relations, except as to property, and except that they may agree in writing to an immediate separation and may make provision for the support of either of them and of their children during such separation. The mutual consent of the parties is sufficient consideration for such separation agreement.
SDCL 25-2-13