Wash. Rev. Code § 78.16.070
In the event said lease shall be for reserved mineral rights on lands previously sold by said county with mineral rights reserved, as provided in RCW 36.34.010, said lease shall contain a provision that no rights shall be exercised under said lease by the lessee, his or her heirs, executors, administrators, successors, or assigns, until provision has been made by the lessee, his or her heirs, executors, administrators, successors, or assigns to pay to the owner of the land upon which the rights reserved to the county are sought to be exercised, full payment for all damages to said owner by reason of entering upon said land; said rights to be determined as provided for in RCW 36.34.010: PROVIDED, HOWEVER, That in the event of litigation to determine such damage, the primary term of such lease shall be extended for a period equal to the time required for such litigation, but not to exceed three years.
RCW 78.16.070