The hook
The PLSS is the gridded property system covering most of the U.S. west of Ohio. Townshipsof 6 mi × 6 mi divide into 36 sections of 1 sq mi (640 ac). Aliquot parts subdivide further — quarter, quarter-quarter, etc. Every PLSS-state surveyor must read this grid fluently.
Memorize these
Concepts that show up on the exam
Township
6 mi × 6 mi block, identified by township + range from the principal meridian and baseline (e.g., T2N R3W).
Section
1 sq mi (640 ac), numbered 1-36 in the boustrophedon order starting NE, ending SE.
Aliquot parts
Quarters and quarter-quarters of a section. Smallest aliquot is the quarter-quarter (40 ac).
Lot
A parcel along the north or west boundary of a township that doesn't come out to a clean aliquot due to convergence/correction lines. Numbered consecutively.
Principal meridian / baseline
The N-S and E-W reference lines from which townships and ranges are counted. Different parts of the country use different principal meridians.
Standard parallel / guide meridian
Correction lines that prevent accumulating convergence error (meridians converge poleward). Standard parallels every 24 mi N-S; guide meridians every 24 mi E-W.
| Aliquot | Acres | Description example |
|---|---|---|
| Section | 640 | Sec 14, T2N R3W |
| Quarter (¼) | 160 | NW¼ of Sec 14 |
| Quarter-quarter (¼ of ¼) | 40 | SE¼ of NW¼ of Sec 14 |
| Quarter-quarter-quarter | 10 | NE¼ of SE¼ of NW¼ of Sec 14 |
Test yourself
How well did it stick?
A quick 5-question check on Public Land Survey System (PLSS). See where you stand and what to review.