Wash. Rev. Code § 53.25.060
With the approval of the county commissioners, any lands in an industrial development district, owned privately, which the port commission deems valuable for industrial development purposes, may be deeded to and accepted by the port district, subject to delinquent general taxes thereon. When the commission has recorded the deed and notified the county commissioners thereof, the county commissioners shall order all taxes assessed against the lands canceled and the county treasurer shall record the cancellation, and remove the lands from the tax rolls. Thereafter the lands shall be held in trust, managed, developed, leased, and sold by the district, and the proceeds therefrom disposed of in the same manner as hereinabove provided.
RCW 53.25.060