Wash. Rev. Code § 52.22.011
The respective areas, organized and established or attempted to be organized and established under the authority granted in Title 52 RCW which since their organization and establishment or attempted organization and establishment have continuously maintained their organization as fire protection districts established under the authority of these statutes are declared to be properly organized fire protection districts existing under and by virtue of the statutes having in each case, the boundaries set forth in the respective organization proceedings of each of them as shown by the files and records in the offices of the legislative authority or authorities and auditor or auditors of the county or counties in which the particular area lies.
RCW 52.22.011