Columbia County Courthouse

230 Strand Street, St. Helens, OR 97051 • Phone: (503) 397-7210 • Toll Free: (888) 397-7210

Columbia County

Assessor's Office

Contact Info

  • Assessor:  Sue Martin

  • Office Hours:  Monday thru Friday, 8:30 a.m. to 5:00 p.m.  We are closed the second Thursday of each month from 8:30 a.m. to 12:00 p.m. for staff work sessions and training.

  • Location: Columbia County Courthouse Annex, 230 Strand, Saint Helens, Oregon

  • Phone: 503-397-2240  Fax: 503-397-5153 

  • Email: This email address is being protected from spambots. You need JavaScript enabled to view it.


Search for Assessment and Tax Data Online


Mass Appraisal Setup Study Summary

The Assessor's appraisal staff spend approximately two months every year analyzing the current market and developing new land schedules, local cost modifiers, depreciation schedules and other costs/adjustments necessary for use in mass appraisal of all residential properties in Columbia County.  This year, these factors will be used to reappraise all residential properties in the Vernonia Area, appraise all residential new construction in the county and to recalculate all remaining residential properties in the county based on existing inventory.  For 2018, a new publication summarizing the setup process, analysis and conclusions for each of these factors has been developed and is available for download below.  The actual raw data used in the analysis and conclusion is available for review in our office.


Publications and Presentations

Team Approach to Mass Appraisal

Faced with continued budget shortfalls and limited resources, Columbia County Property Appraisers developed a more efficient method of inspections that increased productivity and morale while maintaining a safe work environment.  This is a powerpoint presentation video narrated by the appraisal staff.

Recent History of Oregon's Property Tax System

Written by Tom Linhares, retired director of Multnomah County Tax Supervising & Conservation Commission, and previous Columbia County Assessor

Oregon's Property Tax System Summary (narrated video version)

Short video presentation on the changes to Oregon's Property System since 1990 and the limitations of our current system.

Mission Statement

The mission of the Columbia County Assessor's Office is to apportion the cost of supporting local public service districts, on behalf of the patrons of those districts, so no taxpayer is required to pay more or less than their fair share by annually producing an accurate and timely assessment roll that complies with Oregon Revised Statutes and Oregon Administrative Rules.

(Click here to download Adobe Reader)