Wash. Rev. Code § 79.36.480
Should any improvements, made by anyone not holding adversely to the state at the time of making such improvements or made in good faith by a lessee of the state whose lease had not been canceled or was not subject to cancellation for any cause, or made upon the land by mistake, be upon any of such lands at the time of the appraisement, the same shall be separately appraised, together with the damage and waste done to said lands, or to adjacent lands, by the use and occupancy of the same, and after deducting from the amount of the appraisement for improvements the amount of such damage and waste, the balance shall be regarded as the value of said improvements, and the railroad company, if not the owner of such improvements, shall deposit with the department the value of the same, as shown by the appraisement, within thirty days next following the date thereof. The department shall hold such moneys for a period of three months, and unless a demand and proof of ownership of such improvements shall be made upon the department within said period of three months, the same shall be deemed forfeited to the state and deposited with the state treasurer and paid into the general fund. If two or more persons shall file claims of ownership of said improvements, within said period of three months, with the department, the department shall hold such moneys until the claimants agree or a certified copy of the judgment decreeing the ownership of said improvements shall be filed with the department. When notice of agreement or a certified copy of a judgment has been so filed, the department shall pay over to the owner of the improvements the money so deposited.
RCW 79.36.480
Intent-2003 c 334: See note following RCW 79.02.010.