Blog · September 30, 2026
What Is Excess and Deficiency in a Section?
Excess and deficiency are the amounts by which a section or a township line ran longer or shorter than the nominal mile. The original survey placed that leftover by rule, often in the north and west tiers. It is not a mistake you correct by resizing every parcel.
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Miles that were not exact
A nominal section is a mile square. Chains, slopes, and the tools of the time produced lines that ran long or short. The public-land instructions did not pretend otherwise. They told the surveyor where to put the extra or the shortage so the rest of the sections could stay as regular as the plan allowed. In the usual township, the excess or deficiency falls in the northern and western tiers of sections, which is why those sections contain government lots with odd acreages. Interior sections were intended to stay regular. When a deed of an interior forty says forty acres more or less, a small difference may be measurement. When a deed of government lot 2 in section 6 says 37.40 acres, the odd area may be the original plat telling you the leftover was put there on purpose.
How the rule protects the other parcels
If every owner resized a share of a long mile, monuments would stop controlling and every fence would be an argument. The system does the opposite. Recovered original corners control. The excess or deficiency stays where the survey put it. Proportionate measurement, used when a corner is lost, spreads measurement error in a defined way between recovered corners. It is not an invitation to redistribute a township among current owners with a spreadsheet. Private subdivision lots are a different system again. A lot platted at 50 feet stays a platted lot. You do not apply township excess rules to it.
What the assessor’s acre number is doing
Tax software computes an area from the parcel polygon. That number can differ from the patent acres and from a modern survey for ordinary reasons: the polygon is generalized, a road is cut out, or two government lots are combined on one bill. The difference is not proof the government survey shorted your ancestor. Read the official plat acreage next to the deed. If they disagree with a new survey by enough to matter for a sale or a fence, hire a surveyor. Do not slide a fence to capture a GIS sliver you have decided is the excess. A laser measure along a road ditch will not reveal a township’s surplus.
What to do next
- Compare the deed acres with the official plat acres for that lot.
- Note whether the section is on the north or west tier of the township.
- Treat odd government-lot acres as original, not as a typo.
- Ask a surveyor before you treat a shortage as land missing from a neighbor.
The mix-up to avoid
Spreading a long or short mile evenly across every owner because that feels fair. The survey already assigned the leftover. Redistributing it rewrites the plat.
Questions people ask
Does excess mean I own more than the deed says?
It means the original line did not match the nominal mile, and the plat accounted for that. Your deed conveys what it describes, often by lot or aliquot, with area as a secondary phrase. A survey can compute a modern area. It does not amend the patent.
Why is Section 6 so often irregular?
In the standard township layout, Section 6 is the northwest corner, so both the north and the west leftovers can show up there. The township plat, not a rule of thumb, shows the lots and their areas.
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.