Wash. Rev. Code § 35A.14.160
There is hereby established in each county of the state, other than counties having a boundary review board as provided for in chapter 189, Laws of 1967 [chapter 36.93 RCW], a board to be known as the "annexation review board for the county of . . . . . . (naming the county)", which shall be charged with the duty of reviewing proposals for annexation of unincorporated territory to charter code cities and noncharter code cities within its respective county; except that proposals within the provisions of RCW 35A.14.220 shall not be subject to the jurisdiction of such board.
In all counties in which a boundary review board is established pursuant to chapter 189, Laws of 1967 [chapter 36.93 RCW] review of proposals for annexation of unincorporated territory to charter code cities and noncharter code cities within such counties shall be subject to chapter 189, Laws of 1967 [chapter 36.93 RCW]. Whenever any county establishes a boundary review board pursuant to chapter 189, Laws of 1967 [chapter 36.93 RCW] the provisions of this act relating to annexation review boards shall not be applicable.
Except as provided above in this section, whenever one or more cities of a county shall have elected to be governed by this title by becoming a charter code city or noncharter code city, the governor shall, within forty-five days thereafter, appoint an annexation review board for such county consisting of five members appointed in the following manner:
Two members shall be selected independently by the governor. Three members shall be selected by the governor from the following sources:
Each source shall nominate at least two persons for an available position. In the event there are less than two nominees for any position, the governor may appoint the member for that position independently. If, at the time of appointment, there are within the county no cities of one of the classes named above as a nominating source, a position which would otherwise have been filled by nomination from such source shall be filled by independent appointment of the governor.
In making appointments independently and in making appointments from among nominees, the governor shall strive to appoint persons familiar with municipal government and administration by experience and/or training.
RCW 35A.14.160