RCW 76.04.055: Service of notices.

Any notice required by law to be served by the department, warden, or ranger shall be sufficient if a written or printed copy thereof is delivered, mailed, telegraphed, or electronically transmitted by the department, warden, or ranger to the person to receive the notice or to his or her responsible agent. If the name or address of the person or agent is unknown and cannot be obtained by reasonable diligence, the notice may be served by posting the copy in a conspicuous place upon the premises concerned by the notice.