What is the Rectangular Survey System?
Most of the United States (outside the 13 original colonies) has been surveyed using the rectangular survey system or the Public Land Survey System. This is the kind of survey youāll be most likely to work with. In 1785, the Congress of the Confederation enacted a Land Ordinance for the public lands northwest of the Ohio River. The law provided for the survey of public lands into townships of 36 square miles each. The Ordinance also established the use of the Cadastral Survey Plat, a system for recording land patents and related records essential to the chain of title. The rectangular survey system and, in 1800, the tract book system for permanently recording titles became the standard for transferring public lands into private ownership as western migration progressed.
In 1789, Congress established the Treasury Department and gave it responsibility for overseeing the sale of public lands. The General Land Office (GLO) was created in 1812 within the Treasury Department to oversee the sale and transfer of public lands into private hands. The GLO was transferred to the new Department of Interior in 1849. In 1946, the Bureau of Land Management (BLM) was created by merging the GLO and the Grazing Service.
BLM cadastral surveyors still must perform and review surveys of all federal lands being transferred by sale, donation, acquisition, or exchange. The BLM continues to provide GLO land and mineral recordation services for federal lands. The Oregon State Office of the BLM maintains a complete collection of all land status records, cadastral survey records, and mining claim records for Oregon and Washington. The Idaho State Office maintains records for Idaho.
BLM status records are current only for federal lands. Once land leaves federal ownership, subsequent private title transfers, rights, and restrictions are recorded in the appropriate county assessorās office.
How the Rectangular System Works
The rectangular system sets up a grid, with the objective of obtaining approximately square sections of 1 square mile each (1 mile on a side). One mile = 5,280 feet. To understand the rectangular survey system, you need to know about meridians and baselines. Meridians are northāsouth lines, and baselines are eastāwest lines. A principal meridian is a true northāsouth line that runs through an initial point to the limits of the area being covered. At 37 locations in the United States, an initial point has been established where a principal meridian and a baseline intersect. These points were located through astronomical observations and donāt change. Using these 37 points, control can be established for surveys anywhere in the continental United States.
In Oregon and Washington, the rectangular survey system is referenced to the northāsouth Willamette Meridian and to the eastāwest Willamette Baseline. These two lines cross at an initial point called the Willamette Stone, located in the west hills of Portland. In Idaho, the system is referenced to the Boise Meridian and Baseline, the initial point of which is in Meridian, Idaho.
Townships are approximately 6 miles on each side. Theyāre numbered from the baseline, starting with Township 1 North (T1N) north to the Canadian border and Township I South (TIS) south to the California and Nevada state lines. Ranges are numbered from the meridian west (e.g., R1W) and east (e.g., RIE). Thus, a township six grid locations north of the baseline and two grid locations west of the principal meridian would be designated as T6N, R2W Similarly, a township three grid locations south of the baseline and six grid locations east of the principal meridian would be designated as T3S, R6E (Figure 1).
Normal townships contain 36 sections. Each section is approximately 1 mile square and contains 640 acres. (One acre = 43,560 square feet.) All townships use the same system for numbering the sections within them. Sections are numbered beginning with number 1 in the northeast corner, going west to number 6, then south to 7, east to 12, south to 13, and so on (Figure 2).
Every section has four quarter corners, which usually are the midpoint on each of the lines forming the boundaries of the section. Sections can be divided into quarters and halves by connecting these points. With a line drawn northāsouth or eastāwest through the center of a section to connect two quarter corners, the section is divided into halves. Each half is identified by its location in the section (north half, south half, east half, or west half).
Figure 1.āAn example of township and range numbering.
Figure 2.āStandard township plat.
Sometimes the grid isnāt perfect. For example, although every section basically is square and has four corners, these corners may or may not be shared with the adjoining section. And although each section should be 1 square mile and there are 640 acres in 1 square mile, not all sections have 640 acres. How can this be? The reason is that it can be difficult to match edges of adjoining townships if the townships were surveyed at different times. There also need to be adjust- ments because of the curvature of the earth. Often we have offset corners that act as a kind of āfudge factorā to Figure 3.āSection of land (640 acres) showing minor subdivisions and corners. avoid overlapping ownerships; then, With lines drawn northāsouth and eastāwest the result is sections that donāt have exactly through the center of a section to connect 640 acres. These sections generally are along all four quarter corners, the section is the western edge of the township. divided into quarters (Figure 3). Again, each quarter is identified by its location in the section (northeast quarter, southeast quarter, northwest quarter, or southwest quarter).
There you have it...a bit of surveying history for you to chew on. Feel free to add or discuss anything related to the Rectangular Survey System below.
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