S.D. Codified Laws § 56-1-17
Current with legislation signed by the governor on or before 3/6/2024
Where one guarantees a conditional obligation his liability is commensurate with that of the principal, and he is not entitled to notice of the default of the principal unless he is unable, by the exercise of reasonable diligence, to acquire information of such default, and the creditor has actual notice thereof.
SDCL 56-1-17