PS Exam Preparation

Comprehensive preparation for the NCEES Principles and Practice of Surveying (PS) exam. 5 modules covering all 5 exam domains with 50 in-depth topics.

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Lesson 6

Monumentation Standards & Types

Learning Objectives

After completing this topic, you should be able to:

Distinguish between natural and artificial monuments and their evidentiary weight
Identify common monument types used in professional surveying
Explain the legal hierarchy of boundary evidence as it relates to monuments
Describe monument setting standards including materials, marking, and placement
Understand perpetuation requirements for existing monumentation
Apply the doctrine of monuments over other boundary evidence
Determine when monument rehabilitation or replacement is appropriate

Overview

Monumentation is the physical manifestation of surveying work on the ground. While computations exist on paper and coordinates exist in databases, monuments are the tangible markers that property owners, future surveyors, and the public rely upon to identify boundary locations. The professional surveyor must understand not only the technical standards for setting monuments but also the legal principles that govern their evidentiary weight.

The treatment of monuments in law reflects centuries of property jurisprudence. Courts have consistently held that physical monuments on the ground carry greater weight than written dimensions, courses, or areas in resolving ambiguities in property descriptions. This principle, while subject to important exceptions, is fundamental to boundary law and survey practice.

Key Concepts

Natural vs. Artificial Monuments

The distinction between natural and artificial monuments is one of the most important concepts in boundary surveying.

Natural Monuments

Natural monuments are physical features that exist in nature, not placed by human hands for survey purposes. Examples include:

Natural Monument	Characteristics
Rivers and streams	Ambulatory (may shift over time); thalweg or thread of stream
Lakes and ponds	Water's edge at ordinary high or low water
Ridgelines	Topographic divides between drainage basins
Rock outcrops	Permanent, identifiable geological features
Trees (witness/bearing)	Specifically identified trees called for in descriptions
Bays, harbors, shorelines	Subject to tidal and erosion changes
Springs	Point features, relatively stable
Cliffs and bluffs	Prominent topographic features

Natural monuments are generally given the highest evidentiary weight because they are considered the most reliable indicators of the grantor's intent. They were visible at the time of the original conveyance and presumably influenced the parties' understanding of the property boundaries.

However, natural monuments can be problematic:

Ambulatory boundaries (rivers, streams) may shift over time through accretion or avulsion
Destruction by natural forces or human activity may eliminate the monument
Ambiguity in identifying the specific feature called for in the description

Artificial Monuments

Artificial monuments are physical objects placed by human hands. They fall into two categories:

Monuments placed as survey markers:

Monument Type	Material	Typical Use
Iron pipe/rod	Iron, steel, rebar	Property corners, lot corners
Cap and tag	Brass, aluminum, or plastic cap on pipe/rod	Identification with surveyor's license number
Concrete monument	Concrete with embedded marker	Section corners, major boundaries
Stone monument	Cut stone or natural stone with markings	Historical surveys, GLO corners
Nail and shiner	Masonry nail with aluminum disc	Corners in pavement
Axle	Old vehicle axle	Older surveys, section corners
P-K nail	Brass or aluminum nail	Property corners in hard surfaces
Railroad spike	Steel spike	Temporary or rural markers

Monuments of occupation and improvement:

Feature	Evidentiary Role
Fence lines	May indicate practical boundary location or acquiescence
Walls	Stone walls, retaining walls as boundary evidence
Buildings	Corners or edges called for as boundary reference
Roads and streets	Centerline, edge, or right-of-way as boundary reference
Hedgerows	Living fence lines as evidence of boundary location
Irrigation ditches	Channels as boundary features

Figure PS.2.6 — Monument Types and Evidentiary Weight

Legal Hierarchy of Boundary Evidence

Courts have established a general hierarchy for resolving conflicts in boundary descriptions. While the hierarchy varies somewhat by jurisdiction and circumstance, the generally accepted order from highest to lowest priority is:

Natural monuments -- rivers, lakes, ridges, marked trees
Artificial monuments -- stakes, pipes, stones, and other markers called for in the description
Adjoiners and adjoining boundaries -- references to neighboring properties
Courses (bearings/directions) -- the directions of boundary lines
Distances -- the lengths of boundary lines (some authorities rank distances above directions — the relative priority depends on the survey methods used and the jurisdiction; see Topic 1.5)
Area (quantity) -- the stated acreage or square footage

This hierarchy is a guideline for resolving ambiguities, not an absolute rule. The fundamental principle is to determine the intent of the parties at the time of the original conveyance. If a lower-priority element more clearly reflects the parties' intent, it may prevail over a higher-priority element.

Monuments and Deed Interpretation

Monuments Set Prior to Deed

When monuments are set before a deed is written and the deed refers to those monuments, the monuments are considered part of the deed. The deed describes the monuments as they exist on the ground, and the physical position of the monuments controls over written dimensions that may conflict.

This is a critical principle: a monument set prior to the deed and referenced in the deed is presumed superior to courses and distances that conflict with it. The theory is that the grantor intended to convey the land as delineated by the monuments the parties observed, not as might be computed from imperfect written measurements.

Monuments Set After Deed

When monuments are set after a deed is written (such as when a surveyor later stakes a boundary based on the deed description), these monuments do not carry the same evidentiary weight. They represent one surveyor's interpretation of the written description, not the original grantor's intent. They are presumed subordinate to the deed language they purport to interpret.

Common wrong path — giving "set after deed" monuments full hierarchy weight. Not every found monument earns the top of the evidence hierarchy. The rule is: monuments called for in the deed AND set contemporaneously (before or at the time of the original conveyance) take priority over measurements. Monuments set later — by a subsequent surveyor retracing the deed — are interpretations, not original evidence. They can be wrong, they can be displaced, they can reflect flawed reasoning by the later surveyor. Students sometimes treat every rebar or iron pipe on the property as a controlling monument; the exam tests this by describing a "found monument" whose pedigree is unclear or whose date of placement post-dates the deed. Check monument age, pedigree, and whether the deed references it — without that linkage, it is evidence of occupation or of a prior surveyor's opinion, not of the original boundary.

Quick retrieval check — try before reading on.

▶An 1890 deed calls for "N 45° E, 500 ft to a stone post" between two parcels. You find three objects near the expected corner: (a) a weathered stone post that matches the description, (b) a 1975 rebar with a PLS tag, and (c) a 2015 iron pipe with a cap noting "corrected position." Which controls?

The stone post (a) — it is the monument called for in the 1890 deed and matches the description. Its pedigree traces to the original conveyance. Under the hierarchy, an original called-for monument controls over measurements and over any subsequently set monument. The 1975 rebar (b) is almost certainly a later surveyor's attempt to perpetuate or reinterpret the corner; it has no independent authority beyond whatever evidence it documented. The 2015 pipe (c) is explicitly labeled as "corrected" — meaning the placing surveyor believed the existing monuments were wrong and asserted a new position. That unilateral assertion does not override the original evidence. If the stone post is undisturbed and clearly the called-for monument, it controls; the rebar and pipe should be documented on your plat as found (with dates and ownership) but treated as subordinate. Only if the stone post's pedigree or condition is in doubt do the later monuments become relevant.

However, monuments set after a deed can gain evidentiary significance through:

Long acquiescence -- when property owners treat the monumented line as the boundary for an extended period
Subsequent conveyances -- when later deeds reference the monuments
Estoppel -- when parties have relied on the monumented position to their detriment

Lost and Obliterated Monuments

The distinction between lost and obliterated monuments has significant legal consequences:

Classification	Definition	Treatment
Obliterated	Monument no longer visible but its position can be recovered from related evidence (witnesses, measurements, accessories)	Position is restored from available evidence
Lost	Monument whose position cannot be determined from any evidence	Position must be reestablished by proportionate measurement or other legal method

For GLO/PLSS corners, the BLM Manual of Surveying Instructions provides detailed procedures for restoring obliterated corners and reestablishing lost corners, including single and double proportionate measurement.

Monument Setting Standards

Figure PS.2.31 — Monument setting standards

Materials and Durability

Professional monuments must be:

Durable -- resistant to corrosion, weathering, and physical damage
Stable -- not subject to displacement by frost heave, settlement, or disturbance
Identifiable -- clearly marked as survey monuments
Recoverable -- capable of being found by future surveyors

Modern standards generally require:

Standard	Requirement
Material	Iron pipe, rebar, or equivalent durable material
Minimum size	Typically 1/2-inch to 1-inch diameter (varies by jurisdiction)
Minimum length	Typically 18-30 inches (varies by jurisdiction)
Marking	Identification cap with surveyor's license number
Setting depth	Sufficient to resist displacement (typically below frost line)

Cap and Tag Requirements

Most jurisdictions require that monuments set by a licensed surveyor bear a cap or tag with:

The surveyor's license number preceded by "LS" or "PLS" (or equivalent state designation)
The surveyor's name or firm name (in some jurisdictions)
The designation "PLS" or similar professional title

Most state surveying practice acts require that any monument set by a licensed land surveyor be permanently and visibly marked or tagged with the surveyor's license number and professional designation (e.g., "PLS" or "LS").

Placement Criteria

Monuments should be set at:

All property corners
All angle points in the boundary
Points of curvature and tangency on curved boundaries
Intersections of boundaries with roads, easements, and other features
Sufficient intermediate points along long lines to facilitate future recovery

Placement considerations:

Factor	Guidance
Visibility	Place where reasonably findable by future surveyors
Stability	Avoid fill areas, unstable slopes, construction zones
Protection	Consider surface markers, guard stakes, or witness monuments
Accessibility	Balance between security and recoverability
Depth	Below frost line in cold climates, below typical disturbance depth

Perpetuation of Monuments

Figure PS.2.33 — Four corner-perpetuation methods

The obligation to perpetuate existing monumentation is both a legal requirement and a professional responsibility.

Pre-Construction Reference

Before any construction activity that may disturb or destroy monuments, the surveyor must:

Locate all existing monuments in the project area
Reference each monument to stable features outside the construction zone
File a corner record or record of survey documenting the references
Replace or reset monuments after construction is complete
File documentation of the replacement

This requirement applies to all types of construction, including road work, utility installation, grading, and building construction.

Witness Monuments

When a monument cannot be set at the exact boundary position (due to an obstruction, pavement, or other impediment), a witness monument is set nearby. The witness monument must:

Be clearly marked as a witness monument (not the actual corner)
Have a documented relationship to the actual corner position (bearing and distance)
Be placed where it is reasonably secure from disturbance

Reference Points

Reference points (sometimes called ties or accessories) are measurements from a monument to nearby stable features that help in relocating the monument if it becomes obscured or disturbed. Standard practice is to:

Reference each monument to at least two stable features
Record references as bearing and distance
Select features that are likely to remain stable (buildings, utility structures, large trees)
Include references on the record of survey or corner record

Monument Rehabilitation

Figure PS.2.32 — Found vs set monument symbols and meaning

When a surveyor finds an existing monument that is damaged, tilted, partially exposed, or otherwise compromised, the decision to rehabilitate, reset, or replace it requires careful judgment:

Condition	Action	Documentation
Undisturbed, in good condition	Leave in place, reference	Corner record
Tilted but at original position	May straighten carefully, reference	Corner record noting condition
Displaced from original position	Do not use as control; reset based on evidence	Record of survey
Partially destroyed but identifiable	Reference, protect, consider replacement	Corner record or record of survey
Missing but position recoverable	Reset monument at recovered position	Record of survey

Exam Tips

Natural monuments are generally given higher evidentiary weight than artificial monuments in boundary disputes
Monuments set prior to a deed and referenced in it are considered part of the deed
Monuments set after a deed represent the surveyor's interpretation and are subordinate to the deed language
The hierarchy of boundary evidence (monuments, adjoiners, courses, distances, area) is a guide to determine intent, not an absolute rule
An obliterated monument can be restored from evidence; a lost monument must be reestablished
Most states require monuments to be marked with the surveyor's license number and professional designation
Pre-construction monument referencing and post-construction replacement are mandatory obligations
Witness monuments are used when the actual corner position cannot be monumented