Wash. Rev. Code § 15.65.100
The director shall make and publish findings based upon the facts, testimony, and evidence received at the public hearings together with any other relevant facts available to him or her from official publications of the United States or any state thereof or any institution of recognized standing and he or she is hereby expressly empowered to take "official notice" of the same. Such findings shall be made upon every material point controverted at the hearing and/or required by this chapter and upon such other matters and things as the director may deem fitting and proper. The director shall issue a recommended decision based upon his or her findings and shall cause copies of the findings and recommended decision to be delivered or mailed to all parties of record appearing at the hearing, or their attorneys of record.
RCW 15.65.100