Wash. Rev. Code § 30A.44.240
A bank may for the purpose of voluntary liquidation transfer its assets and liabilities to another bank, by a vote, or with the written consent of the stockholders of record owning two-thirds of its capital stock, but only with the written consent of the director and upon such terms and conditions as he or she may prescribe. Upon any such transfer being made, or upon the liquidation of any such corporation for any cause whatever or upon its being no longer engaged in the business of a bank, the director shall terminate its certificate of authority, which shall not thereafter be revived or renewed. When the certificate of authority of any such corporation shall have been revoked, it shall forthwith collect and distribute its remaining assets, and when that is done the director shall certify the fact to the secretary of state, whereupon the corporation shall cease to exist and the secretary of state shall note that fact upon his or her records.
RCW 30A.44.240