Wash. Rev. Code § 21.20.440
Any person aggrieved by a final order of the director may obtain a review of the order in the county in which that person resides or in any other court of competent jurisdiction by filing in court, within sixty days after the entry of the order, a written petition praying that the order be modified or set aside in whole or in part. A copy of the petition shall be forthwith served upon the director, and thereupon the director shall certify and file in court a copy of the filing, testimony, and other evidence upon which the order was entered. When these have been filed, the court has exclusive jurisdiction to affirm, modify, enforce, or set aside the order, in whole or in part. No objection to the order may be considered by the court unless it was urged before the director or there were reasonable grounds for failure to do so. The findings of the director as to the facts, if supported by substantial evidence, are conclusive. If either party applies to the court for leave to adduce additional evidence, and shows to the satisfaction of the court that the additional evidence is material and that there were reasonable grounds for failure to adduce the evidence in the hearing before the director, the court may order the additional evidence to be taken before the director and to be adduced upon the hearing in such manner and upon such conditions as the court may consider proper. The director may modify his or her findings by reason of the additional evidence so taken; and the director shall file any modified or new findings, which if supported by substantial evidence shall be conclusive, and any recommendation for the modification or setting aside of the original order. The commencement of proceedings under this section does not, unless specifically ordered by the court, operate as a stay of the director's order.
RCW 21.20.440