Wash. Rev. Code § 76.14.100
Except when the owner has notified the department in writing that he or she will make payment on the deferred plan, the assessment shall be collected by the department reporting the same to the county assessor of the county in which the property is situated upon completion of the work in that project and the assessor shall annually extend the amounts upon the tax rolls covering the property, and the amounts shall be collected in the same manner, by the same procedure, and with the same penalties attached as the next general state and county taxes on the same property are collected. Errors in assessments may be corrected at any time by the department by certifying them to the treasurer of the county in which the land involved is situated. Upon the collection of such assessments, the county treasurer shall transmit them to the department. Payment on the deferred plan shall be made directly to the department. Such payment must be made by January 31st for any timber or Christmas trees harvested during the previous calendar year and must be accompanied by a statement of the amount of timber or number of Christmas trees harvested and the legal description of the property from which they were harvested. Whenever an owner paying on the deferred plan desires to pay any unpaid balance or portion thereof, he or she may make direct payment to the department.
RCW 76.14.100
Collection of taxes: Chapter 84.56 RCW.