GLO Historic Plat Map

Retrieval System


History of the Public Land Survey System

The rectangular survey system was enacted by the Land Ordinance Act of 1785. Now known as the Public Land Survey System, this system divided the western lands into grid-shaped townships and sections. Surveyed land was sold by the government, providing important revenue for the cash-starved nation. Previous to the Public Land Survey System, land was surveyed using a confusing landmark-based system called metes and bounds.

The Public Land Survey System is coordinate-based, with all distances and bearings made from north-south running meridians and east-west base lines. The largest subdivision of land is the Public Land Survey Township (as opposed to political township), and measures six miles square. Each township is comprised of 36 sections, and each section has an area of one square mile (640 acres).

Office of U.S. Surveyor General

The office of U.S. Surveyor General was created in 1796 to survey lands as the nation expanded westward. In 1836 the office was placed under the jurisdiction of the General Land Office (GLO). In 1849, the GLO was moved under the Department of Interior. The office of Surveyor General was closed in 1925, and surveying responsibilities remained with the GLO. In 1946, the GLO was abolished, and surveying duties transferred to The Bureau of Land Management (BLM).

Surveying in Minnesota

The earliest land surveys in Minnesota were conducted under the jurisdiction of the Surveyor General of Iowa and Wisconsin, headquartered in Dubuque, Iowa. These surveys, completed between 1848 and May 1857 were primarily on land located between the St. Croix and Mississippi rivers or in the southeastern corner of Minnesota.

The Office of Surveyor General of Minnesota was established in 1857 — one year before statehood — and was responsible for conducting the original government survey in the territory and state of Minnesota. The surveyor general’s primary duties were to award contracts for the survey of specified tracts, supervise the field work of the deputy surveyors, prepare the official plats, and manage the accounts of the office.

Because part of Minnesota had belonged to the Northwest Territory and part to the Louisiana Territory, land in the state was subject to two different surveys. Land east of the Mississippi was platted under a survey originating on the Galena Base Line (near the Wisconsin-Illinois border) and was controlled by the 4th Principal Meridian. The survey of land west of the Mississippi commenced on the Clarendon Base Line (running through Clarendon, Arkansas) and was controlled by the 5th Principal Meridian.

The Office of Surveyor General of Minnesota continued to operate until December 1907, when the survey of Minnesota was complete except for some areas in the north of the state. After 1907 the commissioner of the GLO served, ex officio, as Surveyor General of Minnesota, and was responsible for completing the survey and answering questions relating to the survey.

How the Plats Were Created

The survey progressed continuously in some areas and discontinuously in others. The surveyor general and the commissioner of the GLO decided which tracts were to be surveyed in a given fiscal year. Preference was often given to lands that had commercial value and could be sold immediately. The ongoing settlement of Indian lands also affected the process. Often reservation lands were not surveyed until significantly later.

In The Field

Contracts for survey work were awarded to deputy surveyors by competitive bid. The deputy surveyor, with a crew of chainmen, axemen, and a compassman, ran the survey lines in the field and was responsible for erecting survey monuments, marking “bearing trees,” and recording all measurements in his field notes. The deputy surveyor’s work was verified by the surveyor general, and the field notes and plats submitted to the commissioner of the GLO for approval.

Distances were measured using chains and links. Chains measured 66 feet long, with 80 chains equaling one mile. Each chain was made up of 100 links of 7.92 inches each. Alignment was determined using a compass or a solar compass. In areas where measuring by chains was not possible, such as lakes or hilly terrain, distances were calculated using triangulation.

To demarcate the boundaries of townships and sections, surveyors usually placed monuments — typically wooden posts — at township and section corners, and at quarter-section corners. To insure these corners could be found if the posts were destroyed, surveyors marked “bearing trees” nearby the posts. In prairie areas, they built earth mounds around the posts, about three feet high.

When a corner fell in a body of water, a “meander corner” was established, and the true corner then ascertained by triangulation or direct measurement. Meander corners marked the intersection of section lines and a water body. A “witness corner” was used to designate a section or quarter corner when the corner was located where monumentation was impractical.

The deputy surveyor was also responsible for mapping the physical geography of surveyed lands. Plats show lakes, rivers, swamps, waterfalls, and areas of prairie and forest, and other features. In areas with navigable watercourses or sizeable lakes, plats sometimes include surveys of bank meanders. Also occasionally noted are man-made features such as settlements and roads. The deputy surveyor’s field notes include more detailed information, such as soil type, vegetation, and mineral deposits. The field notes have been digitized and are available on-line at:  The original field notes are preserved by the State Archives of the Minnesota Historical Society. Since the original field notes are fragile, and digital copies are available for use, the field notes may only be used with permission of the Minnesota State Archivist.

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