Cal. Health & Safety Code § 8603

If no interment is made in an interment plot which has been transferred by deed or certificate of ownership to an individual owner, or if all remains previously interred are lawfully removed, upon the death of the owner, unless he has disposed of the plot either in his will by a specific devise or by a written declaration filed and recorded in the office of the cemetery authority, the plot descends to the heirs at law of the owner subject to the rights of interment of the decedent and his surviving spouse.