Washington Revised Code Title 79. Public Lands § 79.02.310. Trespasser guilty of theft, when

Every person who willfully commits any trespass upon any public lands of the state and cuts down, destroys, or injures any timber, or any tree, including a Christmas tree as defined in *RCW 76.48.020, standing or growing thereon, or takes, or removes, or causes to be taken, or removed, therefrom any wood or timber lying thereon, or maliciously injures or severs anything attached thereto, or the produce thereof, or digs, quarries, mines, takes or removes therefrom any earth, soil, stone, mineral, clay, sand, gravel, or any valuable materials, is guilty of theft under chapter 9A.56 RCW.