Washington Revised Code Title 78. Mines, Minerals, and Petroleum § 78.08.060. Staking of claim--Requisites--Right of person diligently engaged in search

(1) Before filing such notice for record, the discoverer shall locate his or her claim by posting at the discovery at the time of discovery a notice containing the name of the lode, the name of the locator or locators, and the date of discovery, and marking the surface boundaries of the claim by placing substantial posts or stone monuments bearing the name of the lode and date of location; one post or monument must appear at each corner of such claim; such posts or monuments must be not less than three feet high; if posts are used they shall be not less than four inches in diameter and shall be set in the ground in a substantial manner. If any such claim be located on ground that is covered wholly or in part with brush or trees, such brush shall be cut and trees be marked or blazed along the lines of such claim to indicate the location of such lines.

(2) Prior to valid discovery the actual possession and right of possession of one diligently engaged in the search for minerals shall be exclusive as regards prospecting during continuance of such possession and diligent search. As used in this section, “diligently engaged” shall mean performing not less than one hundred dollars worth of annual assessment work on or for the benefit of the claim or paying any fee or fees in lieu of assessment work in such year or years it is required under federal law, or any larger amount that may be designated now or later by the federal government for annual assessment work.