Wash. Rev. Code § 17.04.190
It shall be the duty of the weed inspector to carry out the directions of the board of directors and to see that the rules and regulations adopted by the board are carried out. He or she shall personally deliver or mail to each resident landowner within such district and to any lessee or person in charge of any land within such district and residing in such district, a copy of the rules and regulations of such district; and he or she shall personally deliver a copy thereof to nonresident landowners or shall deposit a copy of the same in the United States post office in an envelope with postage prepaid thereon addressed to the last known address of such person as shown by the records of the county auditor; and in event no such address is available for mailing he or she shall post a copy of such rules and regulations in a conspicuous place upon such land. A record shall be kept by the weed inspector of such dates of mailing, posting, or delivering such rules and regulations. In case of any railroad such rules and regulations shall be delivered to the section foreman, or to any official of the railroad having offices within the state. Such rules and regulations must be delivered, posted, or mailed by the weed inspector as herein provided at least ten days before the time to start any annual operations necessary to comply with such rules and regulations: PROVIDED, That after such district shall have been in operation two years such rules and regulations shall be delivered to resident landowners only once every three years, unless such rules and regulations are changed.
RCW 17.04.190