Wash. Rev. Code § 36.79.170
The legislative body of any county feeling aggrieved by any action or decision of the board with respect to this chapter may appeal to the secretary of transportation by filing a notice of appeal within ninety days after the action or decision of the board. The notice shall specify the action or decision of which complaint is made. The secretary shall fix a time for a hearing on the appeal at the earliest convenient time and shall notify the county auditor and the chair of the board by certified mail at least twenty days before the date of the hearing. At the hearing the secretary shall receive evidence from the county filing the appeal and from the board. After the hearing the secretary shall make such order as in the secretary's judgment is just and proper.
RCW 36.79.170