Land records · Parcel maps · October 6, 2026
What Is a Section Corner? PLSS Monuments Explained
What is a section corner? The monument where sections meet in the public land survey: how corners were set, what they look like, and why they matter.
What is a section corner? In the Public Land Survey System, a section corner is the monument that marks where sections meet, usually four at once, at the corners of a roughly one-mile-square grid. Section corners were first set by government surveyors with stones, wood posts, mounds, or marked trees, and many have since been replaced with iron pipes and brass or aluminum caps. They are the backbone for locating property in 30 western and midwestern states. This page is general land-records background, not legal advice.
Where section corners fall
A standard township is about six miles square and holds 36 sections. Section corners sit at the intersections of the section lines, about one mile apart. Between them, quarter corners mark the midpoint of each section line. See what is a quarter corner.
What they look like
| Era | Typical monument |
|---|---|
| Original survey | Marked stone, wood post, mound of earth, or pit |
| Later restoration | Iron pipe or rebar, often with a cap |
| Modern | Brass or aluminum cap stamped with section numbers, year, and surveyor license |
Many caps show a small diagram with the section numbers around the corner. Accessories like bearing trees and witness corners helped relocate the corner.
Why section corners matter
Most rural legal descriptions in PLSS states reference sections. A parcel described as “the NE 1/4 of Section 14” depends on where the Section 14 corners are on the ground. A surveyor will search for the original corners, or accepted replacements, before setting property corners.
Lost and obliterated corners
When a corner’s original position cannot be found, it may be obliterated (evidence remains to restore it) or lost (no evidence). Lost corners are reestablished by rules in federal survey guidance, often by proportion between found corners. See what is a lost corner.
Corner records
Many counties keep corner record files, also called corner certificates or tie sheets, describing each section corner, its monument, and measurements to nearby references. These are often available from the county surveyor or online through GIS. They are a valuable starting point before a survey.
If a section corner is on your land
Section corners are often in road intersections, fields, or woods. Protect them. Disturbing a survey monument can be a crime, and replacing one costs money. If construction or a driveway will disturb a corner, contact the county surveyor first.
Section corners and fence lines
In farm country, fence lines and roads often follow section lines, and many rural roads run directly on them. That makes a road intersection a good place to look for a corner, sometimes under the pavement in a monument box. Still, a fence is not proof of a section line. Old fences were often built by eye, and many sit several feet off the true line. A survey that ties to the actual section corners is the only reliable way to know.
Bottom line
A section corner marks where sections meet in the public land survey, about every mile. Originals were stones, posts, or marked trees; many are now capped pipes. These corners control rural descriptions, so surveyors search for them first. Check corner records with your county surveyor and leave monuments undisturbed. Find county maps via the Platbookmapper map.
What is a section corner FAQ
How far apart are section corners?
About one mile in a standard section, though corrections and irregular sections vary.
What does a section corner cap show?
Usually the township, range, section numbers around the corner, year, and surveyor’s license.
Who maintains section corners?
County surveyors in many states keep records and restore corners, often with dedicated funding.
What if I damage a section corner?
Report it to the county surveyor. Disturbing monuments may carry penalties, and restoration can be costly.
Is a section corner the same as a property corner?
Sometimes, but usually not. Property corners are often within sections and set by later surveys.