University of Wisconsin–Madison

PLSS Data

Survey Control Finder (Online Application)

This robust free application is designed as a central point of access for locating Wisconsin Public Land Survey System (PLSS) corners for a variety of counties with access to related attribute information and metadata. Most appealing is the direct linkage, in many cases, to County websites for their corner tie sheets. Survey Control Finder has been endorsed by the Wisconsin County Surveyor’s Association as a vehicle representing statewide county collaborations for displaying and providing access of their progress towards the completion and maintenance of the PLSS in the state.

Survey Control Finder also provides export functions such as KML, Shapefile, CSV, and GeoJSON file formats.

Coordinates of PLSS corners

The ultimate goal is to obtain Survey Grade quality coordinates on all PLSS corners but it must also be understood, that for the current focus of parcel mapping in Wisconsin, alternate accuracies will suffice. The Wisconsin Land Information Program (WLIP) adopted the Survey Grade definition from the Wisconsin County Surveyors Association as part of their 2016 WLIP Strategic initiative Grant application; however, they acknowledged alternative precisions as follows:

Sub-meter: point precision of 1 meter or better

Approximate: point precision within 5 meters or coordinates derived from public records or other relevant information.

Survey Grade Definition: Coordinates collected under the direction of a Professional Land Surveyor, in a coordinate system allowed by 236.18(2), and obtained by means, methods and equipment capable of repeatable 2 centimeter or better precision.

Low-accuracy coordinate values can be derived from maps such as the USGS topo maps. A statewide digital version of these points has been compiled from the 1:24,000-scale map series into a GIS data layer called the LandNet which includes not only PLSS section corners and lines but further has been mathematically subdivided down to nominal 1/4 section polygons (nominally 40 acres each). Analysis by several county surveyors has found that LandNet coordinates are typically within 50 feet of their true positions. This level of accuracy meets standards for the USGS top maps.

For more information on coordinates and/or land surveying concerns contact the County Surveyor. (Prior to the 1990’s much of this work would have been done through traditional traverse work).

Original survey records and maps

The PLSS was put in place on the land by the federal government’s General Land Office (GLO). Surveyor’s hired by the GLO were required to record their work in notebooks of which only a few copies were made. These historical documents are maintained by the state’s Board of Commissioners of Public Lands (BCPL) and by the Wisconsin State Historical Society (SHS). (The GLO was later absorbed into the modern agency called the Bureau of Land Management (BLM) which today manages large areas of land in the western states, retains mineral rights to some lands in Wisconsin, and is the custodian of the “patents” which are the legal documents indicating conveyance of ownership from the Federal Government to the first private owner).

GLO Field notebooks

The notebook pages have been available as microfilm from the SHS and copies of these are known to exist in some county surveyor’ offices. A recent project involving BCPL has resulted in the digital scanning of all of the notebook pages.

GLO Plat maps

Shortly after the field surveys were completed in an area, the notebook contents were used by GLO staff in Chicago to draft plat maps showing the layout of the PLSS in context of noted geographical features such as rivers, lakes, trails, and settlements. These maps have been scanned by the BCPL and made available.

Records at National Archives office in Chicago

During the 1930’s, the Civilian Conservation Corps (CCC) did some field work in support of finding and/or marking of PLSS corners. These projects were primarily in northern forested areas, and the first place to search for records of this work is at the county courthouse. The State Archivist at the Wisconsin State Historical Society is a seconary source and can assist with searches of the National Archives.

Finding modern PLSS monuments in the field

Who to ask for advice; trespass issues

Professionals are the best source for assistance in locating PLSS monuments. Land surveyors work in private practice and many counties and cities have a staff surveyor. Each county has a land information office. Be aware that in reaching the location of some monuments you may be trespassing on private land.

Protecting/reporting disturbance

If you become aware of a PLSS monument that has been disturbed, report this immediately to the county (surveyor or land information office) or municipality (surveyor or engineer). Do not attempt to “repair” or “restore” any such damage as you may actually make matters worse.

Last updated: November 27, 2017