RCW 36.08.060

The county auditors of the respective counties interested in the transfer of territory, as in this chapter provided, are constituted a board of appraisers and adjusters, to appraise the property, both real and personal, owned by the county from which the territory is taken, and to adjust the indebtedness of such county with the county to which such territory is transferred, in proportion to the amount of taxable property within the territory taken from the one county and transferred to the other.