Wash. Rev. Code § 68.32.040
If no placement is made in a plot or right of interment, which has been transferred by deed or certificate of ownership to an individual owner, the title descends to the surviving spouse or state registered domestic partner. If there is no surviving spouse or state registered domestic partner, the title descends to the heirs at law of the owner. Following death of the owner, if all remains previously placed are lawfully removed and the owner did not dispose of the plot or right of interment by specific devise or by a written declaration filed and recorded in the office of the cemetery authority, the title descends to the surviving spouse or state registered domestic partner. If there is no surviving spouse or state registered domestic partner, the title descends to the heirs at law of the owner.
RCW 68.32.040