Oregon Revised Statutes Mineral Resources § 523.270

Any person feeling aggrieved by the assessments made under an assessment ordinance may, within 20 days after the passage of the ordinance levying the assessment by the district board, appeal to the circuit court for the county in which the district is located. The appeal and the requirements and formalities thereof shall be heard, governed and determined, and the judgment thereon rendered and enforced, in the manner provided for appeals from assessments in ORS 223.005 to 223.105 and 223.205 to 223.930. The result of the appeal shall be a final and conclusive determination of the matter of the assessment, except with respect to the district right of reassessment provided by ORS 523.360.