The Public Land Survey System (PLSS)
The Bureau of Land Management (BLM) is part of the United States Department of the Interior. Its responsibilities encompass 262 millions acres of public lands and administration and management of approximately 300 million acres of mineral rights. BLM also maintains the legal status for 331 million acres of reservation created from public lands, such as the national parks, national wildlife refuges, and national forests.
BLM was established on July 16, 1946, by the consolidation of the General Land Office (created in 1812) and the Grazing Service (created in 1934). As steward of nearly half of all federally managed lands, BLM's primary purpose is wisely balancing the use of natural resources. To achieve this goal, BLM selectively disposes, conserves, enhances, and maintains the environmental quality of these public lands. These resources, besides the land itself, include minerals, forest, range, recreation, wildlife, and soil, water, and vegetation. To manage these resources, the Bureau must be able to accurately identify and locate the increasingly valuable areas of land with which it has been entrusted. BLM's Cadastral Survey Program is responsible for the creation, restoration, marking and defining the boundaries of these lands. Cadastral survey is also responsible for the official boundary surveys for all federal agencies who together manage over 700 million acres of land.
Land Ordinance of 1785
In 1785 the Continental Congress enacted the Land Ordinance which set in motion a rectangular survey system to lay out one mile square parcels over all of the federal lands outside the 13 colonies and their western territories. Our present system of public land survey still retains the basic elements set forth in the Land Ordinance of 1785.
Public Land Survey System or PLSS
This rectangular survey system is now know as the Public Land Survey System. Under the cadastral system the public domain is plotted from a principal meridian (running north and south) and base line (running east and west) into a grid of squares approximately 6 miles to the side, called "townships." The township is further divided into sections of one-mile squares containing 640 acres. Sections are numbered 1-36 from the upper right hand corner. The sections can be further subdivided into quarter sections of 160 acres. The quarters can be divided into half-quarters of 80 acres or into quarter-quarter sections of 40 acres, etc. The land description for the following parcel would be written as "NE1/4NW1/4, Sec. 14, T. 2 S., R. 3 W."
Diagram of PLSS