Wash. Rev. Code § 11.80.100
Whenever the owner of such property shall have been absent from the county for a space of seven years and his or her whereabouts are unknown and cannot with reasonable diligence be ascertained, his or her presumptive heirs at law or the legatees and devisees under the will, as the case may be, to whom the property has been provisionally distributed, may apply to the court for a decree of final distribution of such property and satisfaction, discharge and exoneration of the bonds given upon provisional distribution. Notice of hearing of such application shall be given in the same manner as notice of hearing of application for the appointment of trustee and for provisional distribution and if at the final hearing it shall appear to the satisfaction of the court that the owner of the property has been absent and unheard of for the space of seven years and his or her whereabouts are unknown, the court shall exonerate the bonds given on provisional distribution and enter a decree of final distribution, distributing the property to the presumptive heirs at law of the absentee or to his or her devisees and legatees, as the case may be.
RCW 11.80.100