S.D. Codified Laws § 33A-2-23
If any bonus is payable under §§ 33A-2-10 to 33A-2-33, inclusive, to a mental incompetent, the bonus shall be paid to the person who is constituted his or her committee, guardian, curator, or conservator, by the laws of the state of residence of the mental incompetent, or is otherwise legally vested with the care of the mental incompetent. However, if no such committee, guardian, curator, conservator, or other person exists, payment shall be made to the chief officer of any hospital or institution in which the mental incompetent is placed if the officer is authorized to accept moneys for the benefit of the mental incompetent. If no such committee, guardian, curator, or conservator exists, and if the mental incompetent is not in any such hospital or institution, payment shall be made to the person determined by the department to have assumed the major responsibility for the care of the mental incompetent. Any payment under this section shall be held or used solely for the benefit of the mental incompetent.
SDCL 33A-2-23