Wash. Rev. Code § 89.08.200
The term of office of each supervisor shall be three years and until his or her successor is appointed or elected and qualified, except that the supervisors first appointed shall serve for one and two years respectively from the date of their appointments, as designated in their appointments.
In the case of elected supervisors, the term of office of each supervisor shall be three years and until his or her successor is elected and qualified, except that for the first election, the one receiving the largest number of votes shall be elected for three years; the next largest two years; and the third largest one year. Successors shall be elected for three-year terms.
Vacancies in the office of appointed supervisors shall be filled by the state conservation commission. Vacancies in the office of elected supervisors shall be filled by appointment made by the remaining supervisors for the unexpired term.
A majority of the supervisors shall constitute a quorum and the concurrence of a majority is required for any official action or determination.
Supervisors shall serve without compensation, but they shall be entitled to expenses, including traveling expenses, necessarily incurred in discharge of their duties. A supervisor may be removed by the state conservation commission upon notice and hearing, for neglect of duty or malfeasance in office, but for no other reason.
The governing board shall designate a chair from time to time.
RCW 89.08.200