S.D. Codified Laws § 55-4-19
Whenever a trustee shall make a contract which is within his powers as trustee, or a predecessor trustee shall have made such a contract, and a cause of action shall arise thereon, the party in whose favor the cause of action has accrued may sue the trustee in his representative capacity, and any judgment rendered in such action in favor of the plaintiff shall be collectible by execution out of the trust property. In such an action the plaintiff need not prove that the trustee could have secured reimbursement from the trust fund if he had paid the plaintiff's claim. Any beneficiary, or in the case of charitable trusts the attorney general and any corporation which is a beneficiary or agency in the performance of such charitable trust, may intervene in such action and contest the right of the plaintiff to recover.
SDCL 55-4-19