Wash. Rev. Code § 58.28.360
If in any action brought under this chapter, or under said acts of congress, the right to the ground in controversy shall not be established by either party, the court or jury shall so find and judgment shall be entered accordingly. In such case costs shall not be allowed to either party, and neither party shall be entitled to a deed to the ground in controversy, and in such action it shall be incumbent upon each claimant or claimants to establish that he, she, it or they, was or were, an occupant of the ground in controversy within the meaning of said acts of congress at the time of the entry of said townsite in the United States land office, or is or are the successor, or successors in interest of such occupant.
RCW 58.28.360
Conflicting claims-Procedure: RCW 58.28.140.