The notice must also be mailed to each known living heir at law of any person whose remains are interred in the cemetery, if the person's address is known. If the heirs of any person whose remains are interred in the cemetery are unknown or cannot be found, the publication of the notice of the declaration of intent to disinter provided for in section 23-21-06 must be sufficient and proper notice to such persons.
N.D.C.C. § 23-21-10