Geodetic control refers to permanent reference markers placed in the ground and precisely marked, located and documented. These markers provide accurate reference points to support the production of consistent and compatible data collection for surveying and mapping projects. Wisconsin has tens of thousands of survey control monuments placed by numerous agencies over many decades, so the avenues for finding control point information are varied.
ControlFinder provides a central point of access for locating Wisconsin geodetic control data along with, in many cases, direct linkage to the custodian’s website for control data sheets for: Wisconsin Height Modernization Program control, local control established by Wisconsin counties, National Geodetic Survey (NGS) control, historical USGS 3rd order vertical control, Wisconsin Continuously Operating Reference System, and NGS Continuously Operating Reference System.
- App: ControlFinder – Access to various agency control statewide
- National Geodetic Survey – Access to only NGS control
In an effort to support accurate mapping and surveying at the local level, counties added additional control markers based on the High Accuracy Reference Network (HARN) to create User-Densified Networks (UDNs).
NGS provides Information about survey marks (including bench marks) in text datasheets or in GIS shapefiles.
If you are having trouble locating Geodetic Control Points in Wisconsin or need further help, please contact us via e-Mail or at (608) 262-3065.