Wash. Rev. Code § 36.69.420
A park and recreation district may be formed encompassing portions of two or more counties. Such a district shall be known as a joint park and recreation district and shall have all powers and duties of a park and recreation district. The procedures established in this chapter for the formation of a park and recreation district shall be followed in the formation of a joint park and recreation district except as otherwise provided by RCW 36.69.430, 36.69.440, and 36.69.450.
RCW 36.69.420
Severability-1979 ex.s. c 11: "If any provision of this 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 11 s 7.]