Wash. Rev. Code § 58.28.310
Every person, company, corporation, or association, claimant of any town lot or parcel of land, within the limits of such townsite, must present to such judge within three months after the patent (or a certified copy thereof), from the United States has been filed in the office of the county auditor, his, her, or its affidavit, (or by guardian or next friend where the claimant is under disability), verified in person, or by duly authorized agent or attorney, guardian or next friend, in which must be concisely stated the facts constituting the possession or right of possession of the claimant and that the claimant is entitled to the possession thereof and to a deed therefor as against all other persons or claimants, to the best of his or her knowledge and belief, and in which must be stated who was an occupant of such lot or parcel of land at the time of the entry of such townsite at the United States land office, to which must be attached a copy of so much of the plat of said townsite as will fully exhibit the particular lots or parcels of land so claimed; and every such claimant, at the time of presenting and filing such affidavit with said judge, must pay to such judge such sum of money as said judge shall certify to be due for the assessment mentioned in RCW 58.28.300, together with the further sum of four dollars, to be appropriated to the payment of cost and expenses incurred in carrying out the provisions of this chapter, and the said judge must thereupon give to such claimant a certificate, signed by him or her and attested by the seal of the superior court, containing a description of the lot or parcel of land claimed, and setting forth the amounts paid thereon by such claimant. Such judge must procure a bound book for each unincorporated government townsite in his or her county wherein he or she must make proper entries of the substantial matters contained in such certificate issued by him or her, numbering the same in consecutive order, setting forth the name of the claimant or claimants in full, date of issue, and description of the lot or lands claimed.
RCW 58.28.310