ORS § 308A.356
An owner of land desiring designation and exemption of that land from ad valorem taxation as riparian land under ORS 308A.350 to 308A.383 shall make application to the county assessor upon forms prescribed by the Department of Revenue and supplied by the county assessor. The owner shall describe the land for which designation as riparian lands is requested and the current use of the land. The application shall include any other information as is reasonably necessary to properly designate an area of land as riparian land under ORS 308A.350 to 308A.383 with a verification of the truth thereof. Applications to the county assessor shall be made on or before December 31 of the calendar year preceding the first tax year for which such designation is requested. The county assessor shall notify the State Department of Fish and Wildlife if a recorded sale or transfer of the land granted exemption under ORS 308A.350 to 308A.383 occurs for the purpose of determining continued eligibility of the land for the exemption. The State Department of Fish and Wildlife shall notify the county assessor in writing of the finding within 120 days after the date the county assessor's notice is mailed or delivered. Failure of the assessor to notify the State Department of Fish and Wildlife shall not prevent the imposition of the additional tax prescribed by ORS 308A.368(2).
ORS 308A.356