Wash. Rev. Code § 79A.40.010
Every owner or operator of any recreational device designed and operated for the conveyance of persons which aids in promoting entertainment, pleasure, play, relaxation, or instruction, specifically including devices generally associated with winter sports activities such as aerial lifts, surface lifts, and similar devices and equipment, shall construct, furnish, maintain, and provide safe and adequate facilities and equipment with which safely and properly to receive and transport all persons offered to and received by the owner or operator of such devices, and to promote the safety of such owner's or operator's patrons, employees and the public. The owner or operator of the devices and equipment covered by this section shall be deemed not to be a common carrier.
RCW 79A.40.010