Wash. Rev. Code § 2.08.170
Any judge of the superior court of any county in this state who shall hold a session of the superior court of any other county, in pursuance of the provisions of RCW 2.08.140 through 2.08.170 shall be entitled to receive from the county in which he or she shall hold such sessions reimbursement for subsistence, lodging, and travel expenses in accordance with the rates applicable to state officers under RCW 43.03.050 and 43.03.060 as now or hereafter amended. The county clerk of such county shall, upon the presentation to him or her by such judge of a statement of such expenses, verified by his or her affidavit, issue to such judge a certificate that he or she is entitled to the amount thereof; and upon presentation of such certificate to the auditor of such county he or she shall draw a warrant on the current expense fund of such county for the amount in favor of such judge.
RCW 2.08.170
Holding court in another county or district-Reimbursement for expenses: RCW 2.56.070.