Blog · September 30, 2026
What Is a GLO Plat?
A GLO plat is the General Land Office township plat, the official drawing of the rectangular survey for that township. Patents conveyed land by reference to it. It is not a county tax map, and it is not a modern subdivision plat of house lots.
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What the sheet shows
The classic plat draws the township, the sections, the quarter lines where they were surveyed, government lots, meander lines, and cultural or natural features the surveyor noted. Acreages for government lots and for fractional parts are lettered on the lots. The margin carries the meridian, the township and range, the scale, and approval information. Field notes are the companion volume. The plat is the picture. The notes are the measurements, monuments, and bearing trees. Reading one without the other is how people invent corners the survey did not set. Later resurveys by the government can supplement or supersede parts of an original plat. The plat in force for a patent is the one the patent adopted, which is usually the official plat on file when the patent was issued.
How a patent uses it
A patent that grants the southeast quarter of section 14, or government lot 2, according to the official plat, incorporates that plat into the conveyance. The lines and the meanders on the plat become part of what was granted, subject to the rules about water and about what a meander means. You do not need a metes-and-bounds paragraph when the aliquot or lot reference is doing the work. You do need the plat if you want to know the shape. County GIS came along much later. It may trace those old lines well, roughly, or not at all. It is an assessment product. It does not replace the official plat, and Platbookmapper does not host GLO plats. The directory only links to the county viewer.
What people download by mistake
A pretty township map in a history book, a state atlas, or a screenshot of a parcel layer can look like a GLO plat and still be a redraw. Look for the official character of the sheet: the survey data, the lot acreages, the approval. A redraw may have straightened a meander or omitted a closing corner. Use it as a clue, then get the official copy through the federal land-status sources or the repository that holds the plats for that state. Do not scale distances off a shrunken image with a ruler and call them the chainages. The notes have the numbers. A ruler on a scan is not a survey.
What to do next
- Match the plat’s township, range, and meridian to the deed.
- Read government-lot acreages from the plat, not from a tax bill.
- Pair the plat with the field notes for monuments and meanders.
- Keep later resurvey plats separate from the plat the patent named.
The mix-up to avoid
Using the county parcel map as if it were the official plat the patent incorporated. The parcel map is a modern assessment drawing. The patent pointed at the GLO plat.
Questions people ask
Are GLO plats only in western states?
They cover the public-land states surveyed under the rectangular system, which includes much of the Midwest and the South as well as the West. The original colonies generally do not have this plat. If there is no township and range, do not go looking for a GLO plat to explain a colonial deed.
Can one township have more than one GLO plat?
Yes. Supplemental plats, resurveys, and plats of parts of a township exist. The date and the area the sheet covers tell you whether it is the plat your patent used or a later federal survey. Read the title block before you trace lines.
Find the county map
Open Platbookmapper and pick the county that taxes the land. Use that viewer to get the parcel id, then match it to the recorded plat if you need the easements and lot numbers.
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey.