Wash. Rev. Code § 78.60.040
Notwithstanding any other provision of law, geothermal resources are found and hereby determined to be sui generis, being neither a mineral resource nor a water resource and as such are declared to be the private property of the holder of the title to the surface land above the resource, unless the geothermal resources have been otherwise reserved by or conveyed to another person or entity. Nothing in this section divests the people of the state of any rights, title, or interest in geothermal resources owned by the state.
RCW 78.60.040
Findings-Intent- 2013 c 274 : See note following RCW 78.60.030.
Severability-1979 ex.s. c 2: "If any provision of this 1979 act or its application to any person or circumstance is held invalid, the remainder of the act or the application of the provision to other persons or circumstances is not affected." [ 1979 ex.s. c 2 s 2.]