The Rectangular Government Survey System Explained

The Rectangular Government Survey System (RGSS), often referred to as the Public Land Survey System (PLSS), is one of the primary methods used in the United States to describe and locate land. For title insurance professionals, understanding this system is crucial because it forms the basis of legal descriptions for millions of acres across the country. Unlike the metes and bounds system, which relies on physical landmarks and compass bearings, the RGSS utilizes a standardized grid system of intersecting lines.

This system was established to provide a simplified way to track land ownership and facilitate the sale of large tracts of land. On the title exam, you will be expected to identify the components of this grid, understand how sections are numbered, and calculate the total acreage of a property based on its legal description. For a broader look at land descriptions, check out our complete Title Insurance exam guide.

The entire grid system is built upon the intersection of two primary lines. These lines serve as the starting point for all descriptions within a specific geographic region:

• Principal Meridians: These are imaginary lines running North and South. There are several principal meridians across the United States, each with a unique name.
• Base Lines: These are imaginary lines running East and West that intersect the Principal Meridian at a perpendicular angle.

From these starting points, additional lines are drawn at six-mile intervals. Range Lines run parallel to the Principal Meridian (North-South), creating columns called Ranges. Township Lines (also called Tier lines) run parallel to the Base Line (East-West), creating rows called Tiers. The intersection of a Range and a Tier creates a Township, which is the basic unit of the survey.

A township is 36 square miles, divided into 36 individual sections. One of the most common traps on the title exam involves the numbering pattern of these sections. Instead of starting at the top left and moving across every row in the same direction, the RGSS uses a boustrophedonic (snake-like) pattern.

Section 1 is always located in the Northeast corner of the township. The numbering then moves West to Section 6. From Section 6, the numbers drop down to the next row and move East (Section 7 through 12), then drop down and move West again. This ensures that Section 1 is always directly above Section 12, and Section 7 is directly below Section 6.

If you are preparing for these specific diagram questions, you should practice with practice Title Insurance questions to ensure you can identify section neighbors quickly.

Sections are often subdivided into smaller parcels known as aliquot parts. Because a standard section is 640 acres, these subdivisions follow a predictable mathematical pattern:

• Quarter Section: Created by dividing the section into four equal parts (160 acres each). These are described as the NE 1/4, NW 1/4, SE 1/4, and SW 1/4.
• Quarter-Quarter Section: Created by dividing a quarter section into four smaller parts (40 acres each). These are often the standard size for small farms or rural homesteads.
• Halves: A section can also be divided into halves (320 acres), such as the North 1/2 or the East 1/2.

When reading a legal description, you must read it backwards to locate the property on a map, starting with the Section, then the Township/Range, but to calculate acreage, it is easiest to work with the denominators as shown in the tip above.