NEW UPDATES!
OARs governing county retention were updated November 2025. Your Multnomah County Retention Series has been updated accordingly. Please make sure to double check - some series may have new retention periods.
Series Title (Agency Series #)
Description. (Legal Citations)
Retention
Assessment Maps (DART7-002)
Documents all tax lot and ownership information. There are four types of maps included in this records series: an annual blueline, the most recently updated computer plot, the digital computer map, and obsolete maps which may show information not included in the digital system. These maps show the size, shape, location, and extent of each real property account in Multnomah County. (OAR 166-150-0015(7))
Retention:
Retain until superseded or obsolete.
Condemnation Case Records (DART7-009)
Documents property whose ownership and tax status has changed from taxable to non-taxable as a result of government condemnation. Records vary depending on case, but may include petitions or orders of condemnation, maps, property descriptions, staff reports, correspondence, and related documentation. (Unscheduled) (OAR 166-017-0045(2,4)) (MCC § 8.500)
Retention:
Retain permanently - transfer to Archives upon becoming inactive or after 10 years, whichever comes first.
Correction Voucher Source Documents (DART7-010)
Used to locate tax and assessment roll correction vouchers. Shows voucher number, account number, voucher date, and related information. (OAR 166-150-0015(13))
Retention:
Retain 10 years.
Levy Code Maps (DART7-003)
Documents changes in levy codes. Maps show current changes and boundaries of districts. Information is duplicated in part in Taxing District Boundary Change Records. (OAR 166-150-0015(7))
Retention:
Retain until superseded or obsolete.
Property Classification Memos (DART7-004)
Memoranda from Oregon Department of Revenue to the county regarding the tax status of specified properties (often railroad and public utility rights-of-way). Memos show date, legal description of property, action to be taken by the county, and authorization. (Unscheduled) (OAR 166-017-0045(2,4)) (MCC § 8.500)
Retention:
Retain permanently - transfer to Archives upon becoming inactive or after 10 years, whichever comes first.
Property Owner Indexes (DART7-012)
Records used to identify owners of taxable real and personal property in Multnomah County. Indexes show property owner's name, property owner's address, and tax lot. (OAR 166-150-0015(4))
Retention:
Retain permanently.
Property Transfer Records (DART7-005)
Record of any changes to property ownership that would affect the status of tax lots, accounts, or collection. Records include copies of deeds, mortgages, estate records, marriage and divorce records, and other records that show changes in property ownership. These records are also known as Deed Transfers. (OAR 166-150-0166(5)) (OAR 166-017-0045(2,4)) (MCC § 8.500)
Retention:
Retain permanently - transfer to Archives upon becoming inactive or after 10 years, whichever comes first.
Tax and Assessment Roll Corrections (DART7-006)
Records documenting changes to the tax and assessment rolls. Includes copies of the rolls, notations of changes made, voucher documenting changes, and related information. (OAR 166-150-0015(4)) (OAR 166-017-0045(2,4)) (MCC § 8.500)
Retention:
Retain permanently - transfer to Archives upon becoming inactive or after 10 years, whichever comes first.
Tax Lot Cards (DART7-008)
Records documenting changes to the tax and assessment rolls. A tax lot is a property where the full legal description is too long to display on the computer system. The main purpose of these cards is to show the original description and reflect any changes due to division or consolidation. Includes copies of the deed, notations of changes made, voucher documenting changes, and related information. (OAR 166-150-0015(4)) (OAR 166-017-0045(2,4)) (MCC § 8.500)
Retention:
Retain permanently - transfer to Archives upon becoming inactive or after 10 years, whichever comes first.
Tax Rolls (DART7-011)
Series documents the assessment of real and personal property, the determination of tax liability, and the collection of county taxes. Includes tax rolls, assessment rolls, and block books. Separate assessment rolls have not been produced since 1990. Records show property owner; description and value of urban and agricultural land, personal property; assessments, equalizations, and taxes due; and notations on payment and delinquency in payment of taxes. (OAR 166-150-0015(4)) (OAR 166-017-0045(2,4)) (MCC § 8.500)
Retention:
Retain permanently - transfer to Archives upon becoming inactive or after 10 years, whichever comes first.
Taxing District Boundary Change Records (AT5-001)
Records documenting changes in all county taxing district boundaries. Used to apply appropriate tax levies to specific properties and as record of changes to taxing districts. Records include maps showing current and past district boundaries, orders of annexation, charters, levy code changes, correspondence, and related records. Much of this information is contained in the parcel management system. (OAR 166-150-0015(28))
Retention:
AT5-001(a) Notice of Property Tax Levy and Certification of Categorization: Retain 6 years.
AT5-001(b) All other records: Retain 2 years.
(NOTE: Recent division into two parts.)