RCW 86.09.448

Any person, firm, or corporation feeling aggrieved at any determination by said county legislative authority of the classification or relative percentage of his or her or its lands, aforesaid, may have the same reviewed by a proceeding for that purpose, in the nature of an appeal, initiated in the superior court of the county in which the land affected is situated. The matter shall be heard and tried by the court and shall be informal and summary but full opportunity to be heard and present evidence shall be given before judgment is pronounced.