PURPOSE OF COUNTY CARTOGRAPHY

The goal of County Cartography is to maintain accurate assessment records, support fair and equitable taxation, and provide spatial context for property information. While tax maps are valuable tools for assessment and reference, they are not intended to determine legal ownership or resolve boundary disputes.

HISTORY

The assessment cadastre contains the inventory, appraisal, cartographic, and other assessment record elements. Early Oregon assessors who designed and developed the original map systems emphasized that the primary purpose of the cadastral map was — and still is — the discovery, identification, and inventory of real property.*

A major misconception persists: that a cadastral map establishes legal title or ownership of land. This misunderstanding has created significant challenges in maintaining the assessment cadastre. Contrary to popular belief, a cadastral map cannot, and will never, provide indisputable evidence of legal boundaries or ownership.*

To help set expectations, it is important to understand that tax maps are representational tools for assessment purposes only. They reflect how land is assessed, not how it is legally surveyed. Only a licensed surveyor can establish or verify legal property boundaries.

In addition, cadastral maps are updated using recorded deeds, plats, partition maps, annexations, and survey filings. Updates occur continuously as new documents are recorded.

ROLE OF LANE COUNTY CARTOGRAPHERS

Lane County Cartographers are available to help property owners spatially identify their property boundaries on the tax maps. Changes to these maps are made using the legal descriptions from recorded deeds or other ownership documents. Filed surveys by a licensed surveyor are used as verification when discrepancies arise, often due to improved measurement technology compared to the methods used when early settlers first received federal land claims.

Modern cartography relies heavily on Geographic Information Systems (GIS), which allow for more accurate spatial representation and integration of multiple data sources. However, GIS-based tax maps still do not replace the need for legal surveys.

Differences between tax maps and on-the-ground conditions may occur due to historical mapping methods, incomplete early records, or changes in measurement technology over time.

*Information from Oregon Manual of Cadastral Map Standards and Concepts, Second Edition. Chapter 1