GLO Historic Plat Map

Retrieval System


Problems and Inaccuracies

The science of measurement is not absolute and therefore the original surveyors were allowed to perform their work within a certain tolerance.  Errors in measurement, and because meridians converge as they run north, make townships vary in size and shape from a perfect township.

The Intention

The Reality

Tolerance was built into the surveying process.  All surplus or deficiency was allocated to the sections along the north and west boundaries of townships.  For this reason, few of these sections measure exactly 640 acres in size.
Images courtesy of Lisa Hanni, Goodhue County, Land Use Management Department
 Back to History and Origin
Because of errors or malfunction of equipment, some lines did not fall within tolerance. A system of checks and balances aimed to minimize such error, with the Surveyor Generalís Office having the power to withdraw contracts from deputy surveyors whose work showed incompetence. The Surveyor General could then order the plat corrected or the area resurveyed.