Wash. Rev. Code § 30A.49.050
To be effective, a merger which is to result in a state bank must be approved by the stockholders of each merging state bank by a vote of two-thirds of the outstanding voting stock of each class at a meeting called to consider such action, which vote shall constitute the adoption of the charter and bylaws of the resulting state bank, including the amendments in the merger agreement.
Unless waived in writing, notice of the meeting of stockholders shall be given by publication in a newspaper of general circulation in the place where the principal office of each merging state bank is located, at least once each week for four successive weeks, and by mail, at least fifteen days before the date of the meeting, to each stockholder of record of each merging state bank at his or her address on the books of his or her bank; no notice of publication need be given if written waivers are received from the holders of two-thirds of the outstanding shares of each class of stock. The notice shall state that dissenting stockholders will be entitled to payment of the value of only those shares which are voted against approval of the plan.
RCW 30A.49.050