Wash. Rev. Code § 2.12.035
The retirement pay or pension of any justice of the supreme or judge of any superior court of the state who was in office on August 6, 1965, and who retired prior to December 1, 1968, or who would have been eligible to retire at the time of death prior to December 1, 1968, shall be based, effective December 1, 1968, upon the annual salary which was being prescribed by the statute in effect for the office of justice of the supreme court or for the office of judge of the superior court, respectively, at the time of his or her retirement or at the end of the term immediately prior to his or her retirement if his or her retirement was made after expiration of his or her term or at the time of his or her death if he or she died prior to retirement. The widow's benefit for the widow of any such justice or judge as provided for in RCW 2.12.030 shall be based, effective December 1, 1968, upon such retirement pay.
RCW 2.12.035