Legal Land Descriptions in Federal Township and Range System

Terms used in the Township and Range System


Basic unit of the system, a square tract of line one mile by one mile containing 640 acres.


36 sections are ranged in a 6 by 6 array, measuring 6 miles by 6 miles. Sections are numbered beginning with the northeast-most section, proceeding west to 6, then south along the west edge of the township and to the east.


Assigned to a township by measuring east or west of a Principal Meridian

Range Lines

North to south lines which mark township boundaries

Township Lines

East to west lines which mark township boundaries

Principal Meridian

Reference or beginning point for measuring east or west ranges.

Base line

Reference or beginning point for measuring north or south townships.

How the System Works

A specific township is identified as being north or south of a particular baseline and east or west of a particular principal meridian. For example, T3N, R1E of the 3rd Principle Meridian is the third township north of the baseline in the first range east of the Third Principle Meridian. This particular 36 square-mile area is located in southern Illinois. The land description generally starts with the smallest part of the description and proceeds to the largest definition. For example, SE1/4 of NW1/4 of Section 3, T3N, R1E, 3rd PM would be the southeast quarter of the northwest quarter of section 3 in township 3 north, range 2 east of the 3rd Principle Meridian. You may find some irregularly shaped townships and sections which result from surveying errors and other difficulties.

More detail and examples to be posted soon.