What are Section Corners?
What Is a Section Corner?
A section corner is a legally established survey monument created as part of the Public Land Survey System (PLSS). Section corners define the boundaries of land sections within a township and range and serve as the foundational reference points for land ownership, boundary determination, and retracement surveying.
Under the PLSS, each township is divided into thirty-six sections, typically one mile square. The corners that define these sections—including section corners, quarter corners, and other subdivision corners—were originally established by government surveyors and remain the controlling framework for property boundaries today.
Why Section Corners Matter
Section corners are not merely reference points on a map. They are legal monuments that control land boundaries, regardless of measurement discrepancies or modern coordinate systems.
Surveyors rely on section corners to:
Retrace original government surveys
Resolve boundary disputes
Establish subdivision layouts
Tie modern surveys to historic records
Maintain consistency across land records
Because property boundaries depend on these monuments, the accurate identification, preservation, and documentation of section corners is essential.
Original Government Surveys and Monumentation
Most section corners were established during the original government surveys conducted in the 18th and 19th centuries. These surveys created the framework for land ownership across much of the United States.
Original monuments included:
Stone markers
Wooden posts
Bearing trees
Mounds and pits
Over time, many original monuments were disturbed, destroyed, or replaced. However, their recorded positions and descriptions remain legally significant, making historical survey records critical for modern retracement work.
Perpetuation of Section Corners
Perpetuation refers to the process of preserving, restoring, and documenting section corners so they remain identifiable and usable for future surveys.
This may include:
Resetting monuments in their original position
Adding witness markers
Recording updated monument descriptions
Documenting ties to existing evidence
County surveyors often play a key role in the perpetuation of section corners to ensure continuity and public access to reliable survey reference points.
Section Corner Records and Documentation
Section corner records typically include:
Corner record forms
Monument descriptions
Original government field notes
Legal surveys
Subdivision plats
Historic survey documentation
These records provide the evidence needed to evaluate monument location, history, and reliability. Having centralized, organized access to this information is critical for efficient and accurate surveying.
The Role of County Surveyors
County surveyors serve as custodians of public land survey records within their jurisdiction. Their responsibilities often include:
Maintaining section corner records
Recording new monumentation
Providing public access to survey documentation
Supporting private surveyors and government agencies
Well-organized section corner databases help county surveyors fulfill these responsibilities while preserving critical historical information.
Modern Use of Section Corners
Even with the availability of GPS and GIS technology, section corners remain the controlling elements of land boundaries. Modern coordinate systems do not replace monumented corners; instead, they are tied to them.
Surveyors continue to rely on section corners for:
Boundary retracement
Land development
Infrastructure projects
Mapping and GIS integration
Legal land descripti
Accessing Section Corner Records
Reliable access to section corner records allows surveyors to:
Prepare more accurate surveys
Reduce research time
Verify historical evidence
Improve confidence in boundary determinations
Digital section corner databases provide faster retrieval, better organization, and long-term preservation of these essential public records.
Learn More and Explore Records
The Section Corner Program was developed to support the preservation, organization, and retrieval of PLSS section corner records and related survey documentation. By providing centralized digital access, the program helps surveyors and county offices efficiently manage and use these critical records.
To explore available records or learn more about how section corner data is organized, visit the Mapping and Section Corner Program pages on this site.