Wash. Rev. Code § 79.14.390
Prospecting leases or mining contracts referred to in chapter 79.14 RCW shall be as prescribed by, and in accordance with rules adopted by the department.
The department may include in any mineral prospecting lease or mining contract to be issued under this chapter such terms and conditions as are customary and proper for the protection of the rights of the state and of the lessee not in conflict with this chapter, or rules adopted by the department.
Any lessee shall have the right to contract with others to work or operate the leased premises or any part thereof or to subcontract the same and the use of the land or any part thereof for the purpose of mining for valuable minerals or specified materials, with the same rights and privileges granted to the lessee. Notice of such contracting or subcontracting with others to work or operate the property shall be made in writing to the department.
RCW 79.14.390
Intent-2003 c 334: See note following RCW 79.02.010.