S.D. Codified Laws § 34-26-6
The right to dissect the dead body of a human being exists whenever the person dying is at the time of death an inmate of any charitable institution supported by the State of South Dakota, and such person is at the time of death under medical treatment by physicians appointed or under supervision of said authority; provided however, that before such dissection is allowed an order shall be made by the superintendent or person having charge of such charitable institution stating that in his opinion such dissection is necessary or advisable for the purpose of obtaining knowledge of the cause of the death of such person or necessary for the treatment of others; and, before such dissection be allowed the consent of the next of kin of said deceased person shall be obtained, unless said deceased person shall have been neglected or abandoned by said kin for a period of not less than six months next preceding the time of death of such person, and when no inquiry for or in regard to said deceased person shall have been made by the next of kin of said deceased person for a period of six months next preceding the death of such person, such person shall be deemed abandoned for said period.
SDCL 34-26-6