Wash. Rev. Code § 47.42.060
The department shall adopt rules for the erection and maintenance of signs that are visible from the main traveled way of the interstate system and the scenic system and that are permitted by this chapter and other rules for the administration of this chapter consistent with the policy of this chapter and the national policy set forth in section 131, title 23, United States Code as codified and enacted by Public Law 85-767 and amended only by section 106, Public Law 86-342 and the regulations promulgated thereunder by the secretary of commerce or the secretary of transportation. Proceedings for review of any action taken by the department pursuant to this chapter shall be instituted by filing a petition only in the superior court of Thurston county.
RCW 47.42.060