Oregon Revised Statutes Revenue and Taxation § 308.217

(1) For purposes of assessment and taxation, the assessment roll and the tax roll of each county shall be deemed one continuous record. They shall be made up in regular and orderly form, with appropriate headings for assessment of properties, extensions of tax levies, for payments, foreclosures, redemptions, issuance of deeds and other entries as contemplated by law. The rolls shall be in an acceptable form of record keeping, approved by the Department of Revenue, which may be, but is not limited to, bound volumes, numbered loose-leaf sheets, systematic punch cards or magnetic tape. Both rolls may be prepared as continuing rolls, covering two or more years, but all proceedings in the assessment and taxation of property for each year shall be separately exhibited therein.

(2) The records constituting the assessment roll may be combined with or separated from the records constituting the tax roll. The records constituting each roll may be divided, for convenience, between the assessor's office and the tax collector's office, with or without duplication in whole or in part in either office.

(3) The owner of any real property shall, upon request of the assessor, furnish to the assessor a description of the property from which its area can be computed accurately and the location and boundary lines made certain.