Wash. Rev. Code § 35.58.300
If a metropolitan municipal corporation shall be authorized to perform the function of metropolitan parks and parkways, a metropolitan park board shall be formed prior to the effective date of the assumption of such function. Except as provided in this section, the metropolitan park board shall exercise all powers of the metropolitan municipal corporation with respect to metropolitan park and parkway facilities.
The metropolitan park board shall authorize expenditures for park and parkway purposes within the budget adopted by the metropolitan council. Bonds of the metropolitan municipal corporation for park and parkway purposes shall be issued by the metropolitan council as provided in this chapter.
The metropolitan park board shall consist of five members appointed by the metropolitan council at least two of whom shall be residents of the central city. The terms of first appointees shall be for one, two, three, four and five years, respectively. Thereafter members shall serve for a term of four years. Compensation of park board members shall be determined by the metropolitan council.
The requirement to create a metropolitan park board shall not apply to a county that has assumed the rights, powers, functions, and obligations of the metropolitan municipal corporation under chapter 36.56 RCW.
RCW 35.58.300