Township, Range, and Section

Township, range, and section are the three parts of a land description in the Public Land Survey System (PLSS), the rectangular survey system BLM maintains as the basis for legal descriptions of land. A description names the principal meridian, then the township and range, then the section and its subdivisions.

How the grid is built

The system starts from an initial point. A north and south line through that point is the principal meridian. An east and west line through it is the base line. Each principal meridian has its own base line.

• Township lines are established north and south of the base line at 6-mile intervals and numbered north or south from the base line.
• Range lines are established east and west of the principal meridian at 6-mile intervals and numbered east or west of the principal meridian.
• The township and range lines intersect to form a nominal 6-mile square, which is called a township.

Two meanings of township

The word is used two ways. It names the horizontal row north or south of the base line, as in Township 3 North. It also names the 6-mile-square unit between two township lines and two range lines, which is the unit of survey.

Sections

Each township is divided into 36 sections. Each section is nominally 1 mile square and 640 acres. By statute, sections are numbered beginning with number one in the northeast section and proceeding west and east alternately through the township until all thirty-six are numbered (43 U.S.C. 751). Section 1 is in the northeast corner and section 36 is in the southeast corner.

Section lines are normally surveyed from south to north and from east to west, and any excess or deficiency is placed against the north and west boundaries of the township. That is why irregular sections and lots are found along the north and west sides of a township.

Subdividing a section

A section is divided into legal subdivisions of two types, aliquot parts and lots.

• Quarter sections are nominally 160 acres, written NE1/4, NW1/4, SW1/4, and SE1/4.
• Quarter-quarter sections are nominally 40 acres, written for example SW1/4NE1/4.
• Quarter-quarter-quarter sections are nominally 10 acres, written for example NW1/4SW1/4NE1/4.
• Lots are irregular parcels that carry an assigned number. They do not have aliquot characteristics.

Under the general land laws the smallest legal subdivision is the quarter-quarter section of 40 acres or the lot. Under the mining laws it is the quarter-quarter-quarter section of 10 acres.

The comma rule

In an aliquot description a comma means "and the." The absence of a comma means "of the." BLM's land description standard gives the example directly. NE1/4SW1/4SE1/4, written without commas, describes one aliquot part of 10 acres. NE1/4, SW1/4, SE1/4, written with commas, describes three aliquot parts totaling 480 acres. A misplaced comma changes both the land and the acreage.

In mining claim descriptions

The regulations require a mining claim on surveyed land to be described by state, meridian, township, range, section, and by aliquot part to the quarter section (43 CFR 3832.12). Placer claims are described by aliquot part and complete lots. A placer claim located after May 10, 1872, must conform as near as practicable to the rectangular subdivisions of the public land surveys (30 U.S.C. 35).

Nominal is not measured

Every acreage above is nominal. The true area of a section or a lot is the area returned on the official plat of survey. A description that assumes a full 640 acres in a section along the north or west side of a township can be wrong.