Washington Revised Code Title 58. Boundaries and Plats § 58.28.240. Plats--Filing

The plat thereof must be made in triplicate on a scale of not less than eighty feet to an inch, which must be duly certified under oath by the surveyor, one of which must be filed with the county auditor of the county wherein such unincorporated town is situated, one must be deposited in the proper United States land office, and one with such judge. These plats shall constitute public records, and must each be accompanied by a copy of the field notes, and the county auditor must make a record of such plat in a book to be kept by him or her for that purpose, and such county auditor must file such copy of said field notes in his or her office. The said surveyor must number and survey the blocks as divided by the roads, and streets opened and generally used and for which a public necessity exists, at the time of making such survey, and must number the several lots consecutively in each block, and all other parcels of land within said unincorporated town as herein provided, which said numbers must be a sufficient description of any parcel of land represented on said plats. Said survey and plat thereof shall conform as nearly as may be to the existing rights, interest, and claims of the occupants thereof, but no lot in the center or business portion of said unincorporated town shall exceed in area four thousand two hundred feet, and no suburban lot in such unincorporated town shall exceed two acres in area.