Fundamental to a well-reasoned opinion on the location of property boundaries, also known as a survey of property, is being able to properly interpret a deed. Proper interpretation of a deed requires understanding uncertainty.

A deed that purports to convey real property contains many parts, and the land surveyor should have a working knowledge of all of them. But far and away the most important element of a deed to the formation of a well-reasoned opinion on the factual question of location is the description. In fact, many courts have defined a sufficient description of property as one that a reasonably prudent surveyor can locate on the ground.

It is the established rule that the courts will be liberal in construing descriptions of premises conveyed by deed and that a description of land is sufficiently definite and certain if it is possible for a surveyor to ascertain from the description, aided by extrinsic evidence, what property was intended to be conveyed.1

As the Oregon court notes, and many other jurisdictions agree, extrinsic evidence is always in play when it comes to the on-the-ground location of property. In addition, and contrary to what many surveyors have told me they believe, the only purpose of a survey of property via the interpretation of the deed description is to determine “what property was intended to be conveyed.” Intent, as I have said in this column and in many other forums, is “king” when it comes to the interpretation of any written document, but the key to the kingdom is ambiguity. Ambiguity is just another way of saying uncertainty.

The “four corners” doctrine teaches us that the first step in interpreting a deed and what was intended to be conveyed is the document itself. The four corners of the document are to be diligently searched to find intent. The land surveyor focuses primarily, but not exclusively, on the description of the property. Uncertainty plays a crucial role in the proper interpretation of the property description. If the description is clear and unambiguous on its face, then the deed is considered patently unambiguous.

However, as the Oregon court tells us and many jurisdictions agree, a deed may hold latent ambiguities that are only revealed through extrinsic evidence. This happens most often when an attempt is made to apply the deed to the land. If the deed can fit more than one possible location, then true intent can only be ascertained through what the deed says in light of the surrounding circumstances and following the rules of construction.

We consistently have held that what boundaries a deed refers to is a question of law, while the location of those boundaries on the face of the earth is a question of fact. If facts extrinsic to the deed reveal a latent ambiguity, then we determine the intent from contemporaneous circumstances and from standard rules of construction. A basic rule is that boundaries are controlled, in descending priority, by monuments, courses, distances, and quantity, unless this priority produces absurd results. The physical disappearance of a monument does not end its use in defining a boundary if its former location can be ascertained.2

Ambiguities, uncertainty as to location or more than one possible location of the property given the surrounding circumstances, not only hold the key to the proper interpretation of intent, they hold the key to answering the factual question as to location. The boundary establishment doctrines that we have discussed on many occasions depend to a large extent on uncertainty. Boundary by acquiescence and boundary by parol agreement, in particular, require uncertainty as to location in order to settle the location question. The underlying theory of these two doctrines is that the true property line is uncertain or in dispute, and because of the uncertainty or dispute an implied (acquiesced) or parol agreement to settle the location question ends the discussion.

This is a troubling area of practice for many surveyors. One of the evaluation problems for the surveyor is what constitutes uncertainty. As we will discuss, the fact that the boundary may have once been in dispute will resolve itself once the uncertainty question is answered. It appears from case law that there are two kinds of uncertainty--subjective and objective. Understanding the difference between the two is critical to applying these doctrines to a well-reasoned opinion on the location question.

Subjective uncertainty means that the landowners just don’t know where the property boundary is located. There was no attempt to find the true location, such as through the services of a land surveyor; the landowners just decided they didn’t know where the property line was located and they agreed to a location, either by implication or parol, usually memorialized by a fence. In many jurisdictions, subjective uncertainty is all that is needed for the implied or parol agreement to apply. In other words, even though a survey of the property could identify the location of the true property boundary through proper interpretation of the deeds, this is irrelevant. However, in other jurisdictions it is not--more is needed.

This is where objective uncertainty and the land surveyor come into play. When a qualified individual (usually a land surveyor) who is objective (no dog in the fight) finds that the location of the true property line is uncertain (more than one possible location), then the location of the property line is objectively uncertain. This also means that the deed (or deeds) in question contains a latent ambiguity. The usual circumstance will be when two or more surveyors, ostensibly working from the same available evidence, could locate the property line on the ground in more than one location. One of the telltale signs of objective uncertainty is the pincushion corners land surveyors leave behind, although many of these multiple monument corners are established when there are no true ambiguities.

The intent may not be clear from the face of the deed when the deed contains a latent ambiguity which is created when in applying the description to the ground [i.e. surveying], facts extrinsic to the document controvert or in some way render unclear the deed’s apparently unambiguous terms.3

In contrast to objective uncertainty, which most surveyors should be able to recognize even without a competing survey to tell them that there is another possible location of the property line, subjective uncertainty exists in the minds of the landowners, or even the predecessors in title to the current landowners. Resolving this type of uncertainty in many cases may require the ability to read minds or communicate with the deceased. Almost the same could be said for a dispute over the boundary line. How does the surveyor today know about a dispute over the boundary that was settled by a fence being erected 60 years ago? If the true property boundary location is objectively uncertain, this is a moot question.

The objective uncertainty test is a higher threshold for uncertainty that will pass muster under every jurisdictional scheme. It is the lowest common denominator, so to speak. If, however, the jurisdiction within which you practice recognizes subjective uncertainty to settle the location question, then you should know, understand and apply the law that is germane to the practice of land surveying in that jurisdiction, including the appropriate boundary law principles under the circumstances of the particular problem being faced.

I want to caution that the scope of this article is uncertainty relative to the doctrines of acquiescence and parol agreement. Other doctrines of the law and equity can be in play with respect to settling the location question, including practical location, estoppel and repose. Additionally, when a common grantor is involved and conveyances are made with monuments in place, set contemporaneously or even subsequently, the presumption is that the monuments so placed contain no ambiguity as to location even though the paper documents may describe them to be located different from where they are actually found on the ground.

It is the work on the ground, and not on the diagram returned, which constitutes the survey, the latter being but evidence (and by no means conclusive) of the former… That the original lines as found marked on the ground must govern, in determining the location and extent of the survey, is a well-established rule, in general applicable to all cases.4

Acquiescence can also settle the location question relative to monuments in the ground, whether set before, during or after the conveyance, when enough time goes by, reliance has set in and the surrounding landowners have acquiesced to their location as marking the true property corners. And finally, acquiescence is not only a boundary settlement doctrine, it is also an evidentiary tool that helps identify where the property lines were originally laid out vis-à-vis long held occupation, fence lines and other such infrastructure.

Uncertainty plays a major role in the proper interpretation of deeds and the descriptions of property that they contain. Therefore, it is ultimately important that the land surveyor develop the ability to recognize when uncertainty exists and the judgment to discern if the uncertainty is the key to the proper interpretation of the location question. This assumes, of course, that land surveyors are in the business of rendering well-reasoned opinions on the location of property lines and are not simply in the expert measurement business.


  1. Avis Rent a Car v. Department of Revenue, 14 OTR 487, 498 (Ore.Tx.Ct.1998), citing O’Hara v. Brace, 258 Ore. 416, 422, 482 P.2d 726 (Ore.1971).
  2. Theriault v. Murray, 588 P.2d 720, 721, 722 (Me.1991).
  3. Perkins v. Graves, 1993 Me.Super. LEXIS 68, 4 (Me.Super.1993).
  4. Wood v. Starko, 197 S.W.3d 255, 262 (Tenn.App.2006).

Neither the author nor POB intend this column to be a source of legal advice for surveyors or their clients. The law changes and differs in important respects for different jurisdictions. If you have a specific legal problem, the best source of advice is an attorney admitted to the bar in your jurisdiction.