Public Land Survey System
The Public Land Survey System is the rectangular grid used to describe most land in the United States outside the original colonies — including nearly all of Minnesota outside platted subdivisions.
The arithmetic#
A section is one square mile: 640 acres.
A township is six miles square: 36 sections, 23,040 acres.
Sections divide into quarters — 160 acres — and quarters into quarter-quarters of 40 acres.
That last figure explains a great deal about rural Minnesota. Parcel sizes cluster on 40, 80, 120 and 160 acres because those are what the grid produces, and "the back forty" is a quarter-quarter section rather than a figure of speech.
Reading a description#
The northeast quarter of the northeast quarter of section 14, township 112 north, range 24 west.
Read it backwards and it resolves easily:
Range 24 west — the north-south column, counted from the principal meridian.
Township 112 north — the east-west row, counted from the baseline.
Section 14 — one of 36 within that township, numbered in a boustrophedon pattern starting at the northeast corner.
Northeast quarter of the northeast quarter — 40 acres in the corner of that section.
Each step narrows the area by a known factor, so the acreage is calculable from the description alone: 640, then 160, then 40.
The grid is not perfect#
Because the earth is curved and the original surveys were run on foot with chains.
Correction lines were built in to reconcile converging meridians, and sections along them are irregular. Within a township, the discrepancy is generally absorbed by the sections on the north and west edges, which is why those sections contain government lots — irregular parcels with their own numbering rather than clean quarter-quarters.
Water bodies produce the same effect: land abutting a lake is divided into government lots rather than regular subdivisions.
Why it matters in Minnesota property#
Parcel identification numbers in many counties encode section, township and range, which is why PIN formats differ so much between counties.
Twelve-month redemption periods under Minn. Stat. 580.23 subd. 2 attach in part to acreage thresholds, and acreage on rural parcels comes from this system.
Tax-forfeited land is described this way almost universally, and a county sale list is unreadable without understanding it.
Agricultural classification, Green Acres and shoreland rules all key off parcel size and location that the grid defines.
Government lots#
Where the grid could not produce regular subdivisions, the survey created government lots instead — irregular parcels with their own numbering.
Two situations produce them. Sections on the north and west edges of a township, which absorb the discrepancy from converging meridians. And land abutting water, where a lake or river cuts across what would otherwise have been a quarter-quarter.
Government lots are common on Minnesota lakeshore, and they matter practically: their acreage is stated rather than derived, so the neat arithmetic of 640, 160 and 40 does not apply. A description reading "government lot 3" carries whatever acreage the original survey assigned it, and the only way to know is to look.