How the Public Land Survey System Works

The Public Land Survey System (PLSS) is the method used to divide and describe land across 30 US states. If you work with rural property, drilling permits, timber sales, crop insurance filings, or title records in any of those states, you encounter PLSS descriptions constantly — notations like T4N R5E Sec 12 NE that precisely identify a 160-acre parcel on the ground.

This guide covers the full system: where it came from, how the grid is structured, and how to read the notation.

A Brief History: The Land Ordinance of 1785

Before the PLSS existed, land in the original thirteen colonies was described using metes and bounds — a system of compass bearings, natural landmarks, and measured distances. The result was a patchwork of irregular parcels, overlapping claims, and boundary disputes that could take years to resolve in court.

After the Revolutionary War, the newly formed United States held vast territory west of the Appalachian Mountains. Congress needed a way to survey it systematically, sell it to settlers, and raise revenue. The solution was the Land Ordinance of 1785, championed by Thomas Jefferson. It established a rectangular survey system that would impose a regular grid on the land before settlement, not after.

The first surveys began in eastern Ohio, starting from a point where the Ohio River meets the western boundary of Pennsylvania. That initial reference point became the starting line for a grid that would eventually extend across the continent.

Over the next century, as the US acquired territory through the Louisiana Purchase, the Treaty of Guadalupe Hidalgo, and the Oregon Treaty, new surveys were launched from new reference points. Each survey area was anchored to its own principal meridian and baseline. By the time the system reached Alaska in the 20th century, 37 principal meridians had been established.

The Grid Hierarchy

The PLSS works like a coordinate system built from nested rectangles, each level subdividing the one above it. Here is the full hierarchy from largest to smallest:

PRINCIPAL MERIDIAN + BASELINE
         │
         ▼
┌─────────────────────┐
│      TOWNSHIP        │
│   (6 × 6 miles)      │
│   = 36 sections       │
│                       │
│  ┌─────────────────┐ │
│  │    SECTION       │ │
│  │  (1 × 1 mile)    │ │
│  │  = 640 acres      │ │
│  │                   │ │
│  │  ┌─────────────┐ │ │
│  │  │  QUARTER     │ │ │
│  │  │  SECTION     │ │ │
│  │  │ (160 acres)  │ │ │
│  │  │              │ │ │
│  │  │  ┌────────┐  │ │ │
│  │  │  │ QTR-QTR│  │ │ │
│  │  │  │(40 ac) │  │ │ │
│  │  │  └────────┘  │ │ │
│  │  └─────────────┘ │ │
│  └─────────────────┘ │
└─────────────────────┘

Level 1: Principal Meridian and Baseline

Every PLSS survey area is anchored to two reference lines:

• A principal meridian — a north-south line of longitude
• A baseline — an east-west line of latitude

These two lines intersect at an initial point. All townships in that survey area are measured from this intersection. Think of it as the origin point on a graph, with townships numbered outward in four directions.

Level 2: Township (T)

From the baseline, the land is divided into horizontal strips called township tiers, each 6 miles wide. Townships north of the baseline are numbered T1N, T2N, T3N, and so on. Townships south of the baseline are numbered T1S, T2S, T3S.

From the principal meridian, the land is divided into vertical strips called ranges, each 6 miles wide. Ranges east of the meridian are numbered R1E, R2E, R3E. Ranges west are R1W, R2W, R3W.

The intersection of a township tier and a range creates a square area — also called a "township" — that is nominally 6 miles on each side (approximately 23,040 acres). A township is identified by both its tier and range number, such as T4N R5E (Township 4 North, Range 5 East).

For a deeper look at how townships and ranges work, see Townships and Ranges Explained.

Level 3: Section

Each township is subdivided into 36 sections, each nominally 1 mile square and containing 640 acres. Sections are numbered 1 through 36 in a specific serpentine (back-and-forth) pattern that starts in the northeast corner.

A full section reference adds the section number to the township designation: Sec 12, T4N R5E means Section 12 within Township 4 North, Range 5 East.

Learn more about how sections work in Sections — The 640-Acre Building Block.

Level 4: Quarter Section

Each section is divided into four quarter sections of 160 acres each, named by compass direction:

• NE — Northeast Quarter (160 acres)
• NW — Northwest Quarter (160 acres)
• SE — Southeast Quarter (160 acres)
• SW — Southwest Quarter (160 acres)

The 160-acre quarter section was the standard homestead claim size under the Homestead Act of 1862.

Level 5: Quarter-Quarter Section

Each quarter section can be subdivided again into four quarter-quarter sections of 40 acres each. For example, the NE of the NW (often written NENW) is the northeast 40 acres of the northwest quarter — a 40-acre parcel.

For detailed coverage of how quarter sections and aliquot parts work, see Quarter Sections and Aliquot Parts.

The 37 Principal Meridians

Unlike a single national grid, the PLSS uses 37 separate principal meridians, each governing its own survey region. Some cover vast areas across multiple states; others apply to a single state or even part of a state.

Here are some of the most commonly referenced:

Different states may fall under one or more principal meridians. Oklahoma, for example, uses both the Indian Meridian (for most of the state) and the Cimarron Meridian (for the panhandle). See the Oklahoma state page for details on how this works in practice.

Which States Use PLSS?

The PLSS covers approximately 30 states — generally those west of the Appalachian Mountains plus several states in the South. The system was applied to public domain lands as they were surveyed and opened for settlement.

PLSS states include: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Florida, Idaho, Illinois, Indiana, Iowa, Kansas, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Mexico, North Dakota, Ohio, Oklahoma, Oregon, South Dakota, Utah, Washington, Wisconsin, and Wyoming.

States that do NOT use PLSS are primarily the original thirteen colonies and states carved from them (such as Kentucky, Tennessee, Vermont, and West Virginia), plus Texas and Hawaii, which had their own land grant systems.

Note that Ohio is a special case — it has multiple overlapping survey systems because it was where the rectangular survey was first tested. Parts of Ohio use the Virginia Military District (metes and bounds), the Connecticut Western Reserve, and several different rectangular survey grids.

For state-specific details, explore pages like Colorado, Oklahoma, and other state guides.

Common PLSS Formats

PLSS descriptions appear in different formats depending on the industry, the state, and the document. Here are some common patterns you will encounter:

Standard format:T4N R5E Sec 12 NE Township 4 North, Range 5 East, Section 12, Northeast Quarter

BLM format:NE 12 4N 5E 6th PM Same parcel, with the quarter listed first and the principal meridian specified

Deed format (verbose):The Northeast Quarter of Section 12, Township 4 North, Range 5 East of the 6th Principal Meridian

Quarter-quarter (40 acres):NENW Sec 14, T32N R21W The northeast quarter of the northwest quarter of Section 14

Oil and gas format:Sec 22-9N-15W Section 22, Township 9 North, Range 15 West — common on drilling permits and regulatory filings

All of these formats describe specific parcels on the same grid. The notation varies, but the underlying system is consistent.

Why PLSS Matters Today

The PLSS grid is not historical trivia — it is the active framework for legal land descriptions across 30 states. Every day, landmen file drilling permits using section-township-range notation. Real estate agents list rural properties with quarter-section descriptions. Crop insurance adjusters locate damaged fields by PLSS coordinates. Title examiners trace ownership chains back to the original land patent from the General Land Office.

If you work with land in any PLSS state, reading and converting these descriptions is a daily task. A transposed range number on a permit filing can mean a regulatory delay. A misread quarter section on a deed can send a field crew to the wrong location.

Township America converts PLSS descriptions to GPS coordinates using official BLM survey data, covering all 30 states and all 37 principal meridians. Whether you need to convert a single description from a deed or batch-process thousands of locations from a spreadsheet, the converter handles the full range of PLSS formats.

Try the PLSS Converter →