Public Land Survey System · 5 min read

Corner monuments, accessories, and bearing trees

What the original surveyors actually set at a PLSS corner, how they marked it, and how accessories such as bearing trees let a lost-looking corner be recovered.

A corner is only as findable as the things left to mark it. The original surveys ran across a continent with hand tools and a wagon, so the monuments they set were whatever the country provided: a wooden post driven in the ground, a stone set on end, a mound of earth or stone, a charred stake, a marked tree. None of those survive well. What often does survive is the accessories, the secondary marks set nearby precisely so the corner could be found again after the monument was gone.

This is why an experienced retracement surveyor spends more time looking for accessories than for monuments. A rotted post leaves nothing, but the bearing trees recorded at 22 links and 31 links from it may still be standing, or their stumps may still be in the ground with the scribe marks intact under sixty rings of growth.

What was set at the corner

The instructions in force at the time of any given survey specified the monument, and the specification changed over the decades. Broadly, the sequence runs from perishable to durable.

Corner monuments in rough historical order
MonumentTypical periodSurvival
Wooden post, often marked and set with a moundEarliest surveys onwardPoor; usually gone within decades, sometimes leaving stain or fragments
Stone set on end, marked with grooves and notchesWherever stone was availableGood, but easily moved by cultivation or road work
Marked tree used as the corner itselfTimbered countryModerate; recoverable while the tree or stump remains
Mound of earth or stone with pits at recorded bearingsPrairie and treeless countrySometimes detectable as a soil or vegetation signature long after
Charred or charcoal-marked stake, deposit of charcoalUsed as a memorial beneath the monumentOften the longest-lived trace of all, since charcoal does not decay
Iron post with a marked capTwentieth century onwardGood, and normally the monument recovered in modern work
Brass or aluminium cap on an iron pipe, stamped with the corner identityModern federal practiceExcellent, and stamped with enough information to identify the corner

Note the charcoal. Where the instructions called for it, a deposit of charcoal was placed in the pit beneath the monument as a memorial, on the reasoning that charcoal is chemically inert and will remain in the soil indefinitely. Careful excavation at a suspected corner position can recover a charcoal deposit long after every other trace has vanished, and it is admissible evidence of the corner.

How monuments were marked

Monuments were marked so they could be identified, not merely found. A corner post or stone carried the identity of the corner scribed or grooved into it: the section number or numbers, and frequently the township and range. On posts, notches cut into the edges recorded position in the township, with the number of notches on a given edge indicating the number of miles to the township boundary in that direction.

The point of the marking system was that a surveyor arriving alone, without the plat, could read the monument and know exactly which corner he had found. The same is true today of a stamped federal cap. When you recover a marked monument, record the marking in full before doing anything else; the marking is often the only evidence of which corner it is.

Accessories

Accessory
A physical object recorded in the field notes with a bearing and distance from the corner, placed or adopted so the corner position can be recovered if the monument is destroyed. Accessories are part of the monumentation and carry the same evidentiary standing.
Bearing tree
A tree near a corner, blazed and scribed with the corner's identity, whose species, diameter, bearing and distance from the corner are recorded in the field notes. Ordinarily up to four were taken, one in each of the sections meeting at the corner.

Bearing trees were the workhorse accessory in timbered country. The surveyor blazed the face toward the corner, scribed the corner identity into the blaze, and recorded the species, size, bearing and distance. Because the scribing is cut into the living wood and the tree then grows over the blaze, the marks are frequently preserved intact beneath decades of overgrowth. A carefully cut window into the overgrowth on the correct face can expose them.

  • In treeless country, bearing objects were used instead: a boulder, a rock outcrop, or another durable feature, with its bearing and distance recorded.
  • Where nothing suitable existed, mounds of earth or stone with pits dug at recorded bearings and distances served the same referencing purpose.
  • Memorials, such as charcoal, glass, stoneware or a marked stone, were deposited beneath or beside the monument as a permanent underground record.
  • Modern accessories are reference monuments set at recorded bearings and distances and reported on a corner record.
  • Every accessory is only useful with the field notes that record it. Accessory work and record research are the same job.

Searching for a corner in practice

  1. Read the original field notes for the corner and for the corners on either side of it, and note every accessory with its species or description, bearing and distance.
  2. Read every later record: dependent resurveys, corner records, county filings, plats of survey, and highway or railroad records that may have referenced the corner.
  3. Compute a search position from the best available control, and treat it as the center of a search area, not as an answer.
  4. Search for accessories first. A single recovered bearing tree with legible scribing fixes the corner far better than a computed position.
  5. Search for physical traces of the monument: a stone in a fence line, a depression where a pit was dug, a mound signature, a change in soil color, decayed wood, a charcoal deposit.
  6. Interview long-term occupants and neighbouring landowners about fences, rock piles and previous surveys, and record what they say.
  7. Only when all of this is exhausted should the corner be treated as lost and restored by proportionate measurement.

Perpetuating what you find

When you recover an original corner or its accessories, the work is not finished until the recovery is recorded so the next surveyor can repeat it. That means measuring and describing every accessory found, setting new accessories or reference monuments if the old ones are failing, photographing the evidence, and filing a corner record where the jurisdiction provides for one.

The original surveyors understood that they were writing a record for people not yet born, which is why they scribed trees and buried charcoal instead of simply driving a stake. A retracement that recovers original evidence and then leaves no durable trace of the recovery has taken value out of the system without putting any back.

Questions

What is a bearing tree?

A tree near a corner that was blazed and scribed with the corner's identity, with its species, size, bearing and distance recorded in the field notes so the corner can be recovered if the monument is gone.

Why is charcoal found under some corners?

It was deposited deliberately as a memorial. Charcoal does not decay, so it can be recovered by careful excavation long after posts, stones and trees have disappeared.

Do accessories carry the same weight as the monument?

They are part of the monumentation and are strong evidence of the corner position. A corner recovered from well-identified accessories is recovered, not restored by proportion.

What should I record when I find an original monument?

The full marking on the monument, its condition and orientation, every accessory found with measured bearing and distance, photographs, and a filed corner record so the recovery can be repeated.

Sources

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