Townships and land sections are part of the rectangular survey system developed by Thomas Jefferson and approved by Congress in 1785. Under this system the land was divided into square areas for surveying and mapping. This system is still the basis for all surveys of public lands.
Find the north and south guideline, called township, and the west and east guideline, called range. The largest square area is the township. Each township measures 6 miles square and is 23,040 acres.
Identify the sections by looking for the numbers 1 to 36. Each township is divided into 36 sections. The sections are each 1 mile square and 640 acres.
Each 640-acre section can further be divided into quarters of 160 acres each. And each quarter can be divided into four 40-acre areas.
Under the rectangular survey system, a 40-acre lot of land can be described by its position within a section, township and range. For instance, NE 1/4 (northeast or top right corner) of the SE 1/4 (southeast or bottom right corner) of section 12, T2N (township) and R3W (range).