Oregon Revised Statutes Revenue and Taxation § 312.010

(1) Except as otherwise provided by law, real property within this state is subject to foreclosure for delinquent taxes whenever three years have elapsed from the earliest date of delinquency of taxes levied and charged thereon.

(2) All special assessments, fees or other charges charged against the property subject to foreclosure which are due and unpaid for any year or years for which ad valorem taxes are delinquent and for which there is no other provision of law for their payment out of the foreclosure proceeding, shall be listed with the delinquent ad valorem taxes in the foreclosure proceedings and foreclosed and collected as a part of such proceedings in the same manner as the delinquent ad valorem taxes. In any event, if three years have elapsed since the special assessment, fee or charge has been placed on the tax roll for collection and the assessment, fee or charge remains unpaid, it may be included in the next foreclosure proceeding and foreclosed and collected as part of such proceeding.