S.D. Codified Laws § 55-3-23
Termination of trust
In addition to the methods specified in §§ 55-3-24 to 55-3-27 , inclusive, a trust terminates if:
(1) The term of the trust expires;
(2) The trust purpose is fulfilled;
(3) The trust purpose becomes unlawful or impossible to fulfill; or
(4) The trust is revoked.
Source: SL 1998, ch 282, § 1; SL 2016, ch 231, § 21.