S.D. Codified Laws § 59-7-2.1
Notwithstanding § 59-7-2, a principal may designate another as the principal's attorney-in-fact or agent pursuant to the provisions of § 59-12-3.
A principal may designate any other person as the principal's attorney-in-fact or agent for health care decisions, and the attorney-in-fact shall have the authority to make any health care decision at any time during which the principal lacks capacity. Any durable power of attorney for health care shall be signed by the principal or in the principal's conscious presence by another individual directed by the principal to sign the principal's name on the power of attorney. The signature shall be witnessed by two other adult individuals or by a notary public. A power of attorney granted pursuant to this section may authorize the attorney-in-fact to consent to, to reject, or to withdraw consent for health care, including any care, service, or procedure to maintain, diagnose, or treat a person's physical or mental condition.
SDCL 59-7-2.1