Washington Revised Code Title 58. Boundaries and Plats § 58.08.010. Town plat to be recorded--Requisites

Any person or persons, who may hereafter lay off any town within this state, shall, previous to the sale of any lots within such town, cause to be recorded in the recorder's office of the county wherein the same may lie, a plat of said town, with the public grounds, (if any there be,) streets, lanes and alleys, with their respective widths properly marked, and the lots regularly numbered, and the size stated on said plat.