S.D. Codified Laws § 34-26-79
Any person signing a funeral service agreement, cremation authorization form, or any other authorization for disposition is deemed to warrant the truthfulness of any facts set forth therein, including the identity of the decedent whose remains are to be buried, cremated, or otherwise disposed of, and the party's authority to order the disposition. A funeral home shall have the right to rely on the funeral service contract or authorization and shall have the authority to carry out the instructions of the person or persons whom the funeral home reasonably believes holds the right of disposition. The funeral home shall have no responsibility to contact or to independently investigate the existence of any next-of-kin or relative of the decedent. If there is more than one person in a class who is equal in priority and the funeral home has no knowledge of any objection by other members of such class, the funeral home shall be entitled to rely on and act according to the instructions of the first such person in the class to make funeral and disposition arrangements; provided that no other person in such class objects in writing to the funeral home.
SDCL 34-26-79