Public Land Survey System (PLSS) : History, Development and Examples (Especially for GATE-Geospatial 2022)

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History of Public Land Survey System

The final plane or rectangular grid system in common use in the United State is Public Land Survey System (PLSS) , established in 1785. The PLSS is the surveying method developed and used in the United States to plat, or divide, real property for sale and settling.

It was meant as a tool for recording ownership of land. Its basic unit of measure is an area of of a square mile or 1 acre.

Survey Design

The surveying of any regional area, such as a state or two, is a multi-step process. First, two controlling survey lines are established: a baseline, which runs east-west and a principal meridian, which runs north-south.

Next, at a defined distance interval, commonly 24 or 30 miles (48 km) depending on the year and location, standard parallels of latitude are established parallel to the baseline.

Survey Design

Each square mile of area is called a section and sections are grouped in larger, 36 square mile groups that collectively called township. The sections are numbered in from 1 to 36. Each of the 36 sections can be divided and subdivided into halves and quarter or quarter of a quarter.

For example: A person can own a quarter of a quarter of a quarter sections means that is 10 acres.

One could also have quarter of half of a section.

Township and their smaller, square mile sections are located with a larger grid of established horizontal and vertical lines. The horizontal lines are called baselines and vertical lines are called principal meridian.

Congressional Township Rectangular Survey Grid

In figure, starting at the Principle Meridian and Base Line a surveyor marked off the township lines into grids of 36 square miles.

Township Grid

Townships were further divided into sections of one square mile (640 acres) . Standard sections were then numbered from 1 to 36. Sections were subdivided into a variety of sizes, most often rectangular in shape.

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