Retracement & Restoration

Overview#

Retracement is the process of recovering the boundaries of an original survey by locating its corners and retracing its lines. In the PLSS, retracement is governed by a fundamental principle: the original survey created the boundaries, and the retracing surveyor's duty is to follow in the footsteps of the original surveyor -- not to create a new survey or to correct the original one.

This principle is codified in the Act of February 11, 1805, which declares that the corners and lines of the original survey are the legal boundaries, regardless of their accuracy. The surveyor conducting a retracement must understand the evidence hierarchy, the classification of corners, and the methods for restoring corners that can no longer be directly recovered.

"The rules for identifying the lines and corners of an approved official survey differ from those under which the survey was originally made. The purpose is not to 'correct' the original survey by determining where a new or exact running of the line would locate a particular corner, but rather to determine where the corner was established in the beginning." -- BLM, Manual of Surveying Instructions (2009), Sec. 6-1

The Duty of the Retracing Surveyor#

Original Survey vs. Retracement

The distinction between an original survey and a retracement is the most important concept in PLSS surveying:

• An original survey creates boundaries. The government surveyor, acting under the authority of the United States, establishes the corners and lines that define the legal subdivisions. Once accepted and filed, these corners and lines are the law of the land.
• A retracement recovers boundaries. The retracing surveyor -- whether a BLM cadastral surveyor or a local licensed surveyor -- seeks to determine where the original corners were placed and where the original lines were run. The retracing surveyor has no authority to move, alter, or "correct" the original survey.

"There is no realm of the law in which there is a greater need to maintain stability and continuity than with regard to property rights and the location of real property boundaries." -- BLM, Manual of Surveying Instructions (2009), Sec. 6-1

Stability of Boundaries

The statutory foundation for this principle is the Act of February 11, 1805:

"All the corners marked in the surveys, returned by the Secretary of the Interior or such agency as he may designate, shall be established as the proper corners of sections, or subdivision of sections, which they were intended to designate; and the boundary lines, actually run and marked in the surveys returned by the Secretary of the Interior or such agency as he may designate, shall be established as the proper boundary lines of the sections, or subdivisions, for which they were intended, and the length of such lines as returned, shall be held and considered as the true length thereof." -- Act of February 11, 1805 (2 Stat. 313; 43 U.S.C. 752), quoted in BLM, Manual of Surveying Instructions (2009), Sec. 6-1

This means that even if the original survey was imperfect -- if a line was not truly cardinal, or a distance was not exactly 80 chains -- the survey as executed is the legal boundary. The retracing surveyor must find where the corners actually were, not where they should have been.

Classification of Corners#

Every corner encountered in a retracement falls into one of three categories: existent, obliterated, or lost. The classification determines the procedure the surveyor must follow.

Existent Corners

An existent corner is one whose original position can be identified by substantial evidence of the monument or its accessories, by reference to the description in the field notes, or by an acceptable supplemental survey record, physical evidence, or reliable testimony.

"An existent corner is one whose original position can be identified by substantial evidence of the monument or its accessories, by reference to the description in the field notes, or located by an acceptable supplemental survey record, some physical evidence, or reliable testimony." -- BLM, Manual of Surveying Instructions (2009), Sec. 6-11

The standard of proof is substantial evidence -- "such relevant evidence as a reasonable mind might accept as adequate to support a conclusion." This is more than a scintilla but less than a preponderance.

An existent corner is controlling. Its position is accepted and used as a fixed point in the retracement.

Obliterated Corners

An obliterated corner is one where no traces of the monument or its accessories remain at the original position, but the position can be recovered through:

• Reliable testimony of witnesses who have dependable knowledge of the original position.
• Later marks or records that tied to the original monument or its accessories when still present.
• Acceptable evidence that provides a direct relationship to some identifying feature described in the original survey record.

"An obliterated corner is an existent corner where, at the corner's original position, there are no remaining traces of the monument or its accessories but whose position has been perpetuated, or the point for which may be recovered, by substantial evidence from the acts or reliable testimony of the interested landowners, competent surveyors, other qualified local authorities, or witnesses, or by some acceptable record evidence." -- BLM, Manual of Surveying Instructions (2009), Sec. 6-17

An obliterated corner is treated as a found corner once its position is satisfactorily recovered. The distinction from a lost corner is that some reliable evidence -- beyond the mathematical methods of proportionate measurement -- ties the position to the original survey.

Lost Corners

A lost corner is one whose original position cannot be determined by any direct or collateral evidence. Neither the monument nor its accessories survive, no testimony or records identify the location, and the corner can only be restored by reference to other interdependent corners using proportionate measurement.

"A lost corner is one whose original position cannot be determined by substantial evidence, either from traces of the original marks or from acceptable evidence or reliable testimony that bears upon the original position, and whose location can be restored only by reference to one or more interdependent corners." -- BLM, Manual of Surveying Instructions (2009), Sec. 7-2

The key principle: a corner must not be classified as lost until every means of recovering its position has been exhausted.

"No decision will be made in regard to the restoration of a corner until every means has been exercised that might aid in identifying its true original position." -- BLM, Manual of Surveying Instructions (2009), Sec. 6-16

Methods for Restoring Lost Corners#

Single Proportionate Measurement

Single proportionate measurement is used to restore a lost corner that lies on a line between two identified (existent or obliterated) corners. The method distributes the excess or deficiency in measurement proportionally along the line.

"The term 'single proportionate measurement' is applied to a new measurement made on a line to determine one or more positions on that line." -- BLM, Manual of Surveying Instructions (2009), Sec. 7-16

The formula for single proportionate measurement is:

$d_{\text{restored}} = d_{\text{record}} \times \frac{D_{\text{measured}}}{D_{\text{record}}}$

where:

• $d_{\text{restored}}$ = the proportioned distance from the first controlling corner to the restored corner
• $d_{\text{record}}$ = the record distance from the first corner to the lost corner
• $D_{\text{measured}}$ = the total measured distance between the two controlling corners
• $D_{\text{record}}$ = the total record distance between the two controlling corners

Applications of single proportionate measurement:

Double Proportionate Measurement

Double proportionate measurement is used to restore a lost corner at the intersection of two lines -- typically a lost section corner in the interior of a township. It uses four controlling corners: two on the meridional line (north and south) and two on the latitudinal line (east and west).

"The term 'double proportionate measurement' is applied to a new measurement made between four known corners, two each on intersecting meridional and latitudinal lines, for the purpose of relating the cardinal equivalents intersection to both." -- BLM, Manual of Surveying Instructions (2009), Sec. 7-8

The procedure:

1. Determine the latitude (north-south position): Proportion the record north-south distance using the controlling corners to the north and south, reducing distances to their cardinal equivalents (north-south components only).
2. Determine the departure (east-west position): Proportion the record east-west distance using the controlling corners to the east and west, reducing distances to their cardinal equivalents (east-west components only).
3. Locate the restored corner at the intersection of lines extended east-west from the latitude proportion point and north-south from the departure proportion point.

Cardinal Equivalents

A critical concept in proportionate measurement is the cardinal equivalent. Because section lines are not perfectly cardinal, the distances used in proportioning must be reduced to their north-south (latitude) and east-west (departure) components. Using the full measured distance along a non-cardinal line would introduce error.

"Use of cardinal equivalent employs only the northerly components (latitudes) of the north and south controlling record lines to compute the latitudinal position, and only the easterly components (departures) of the east and west controlling record lines to compute the longitudinal position." -- BLM, Manual of Surveying Instructions (2009), Sec. 7-9

For a line with bearing $\alpha$ and distance $L$:

$\text{Latitude (N-S component)} = L \times \cos(\alpha)$

$\text{Departure (E-W component)} = L \times \sin(\alpha)$

Three-Point and Two-Point Control

When fewer than four controlling corners are available:

• Three-point control: Used when a line has not been established in one direction from the lost corner. The record distance to the nearest identified corner in the missing direction is used, along with proportionate measurement between the other two corners.

• Two-point control: Used when lines have been established in only two directions. Record distances (reduced to cardinal equivalents) to the nearest identified corners on the intersecting lines control the position.

"Where the line has not been established in one direction from the lost township or section corner, 'three-point control' should be used to reestablish the position of the corner." -- BLM, Manual of Surveying Instructions (2009), Sec. 7-13

The Grant Boundary Rule

Special rules apply to corners on grant boundaries, reservation boundaries, and other special survey lines. These corners are restored according to the law under which the boundary was created, which may differ from the standard PLSS proportioning rules. The surveyor must identify the controlling law for each boundary segment.

The Role of Field Notes and Plats#

The field notes and plat of the original survey are the official record. They describe the corners established, the lines run, the distances measured, the bearings observed, and the topographic features encountered. In retracement, the field notes are the primary source for determining what the original surveyor did.

"The records of official surveys fall under the doctrine of presumption of regularity; that is, the official record is correct unless it is established otherwise by a preponderance of the evidence." -- BLM, Manual of Surveying Instructions (2009), Sec. 6-3

The field notes provide:

• Corner descriptions: The type, material, dimensions, and markings of each monument.
• Accessories: The species, size, direction, and distance of bearing trees and other accessories.
• Topographic calls: Distances to streams, roads, ridges, and other features crossed by the survey lines.
• Distances: The measured length of each line segment in chains and links.
• Bearings: The observed direction of each line.

Using Topographic Calls

Topographic features noted in the original field notes can help the retracing surveyor verify corner positions:

"The proper use of topographic calls of the original field notes may assist in recovering the locus of the original survey. Such evidence may merely disprove other questionable features or be a valuable guide in arriving at the immediate vicinity of a line or corner." -- BLM, Manual of Surveying Instructions (2009), Sec. 6-23

However, topographic calls must be used with caution. Distances to topographic features in the original notes were often estimated rather than measured, and the features themselves may have changed over time.

Collateral Evidence#

When direct evidence of a corner (the monument and its accessories) has been destroyed, the surveyor turns to collateral evidence -- indirect evidence that can help establish the corner's position.

Good Faith Locations

A key form of collateral evidence is the good faith location -- evidence that a landowner or local surveyor located boundaries with reasonable care and diligence based on the evidence of the original survey available at the time.

"It may be held generally that the claimant, entryman, or owner of lands has located his or her lands by the good faith location rule if such care was used in determining the boundaries as might be expected by the exercise of ordinary intelligence under existing conditions." -- BLM, Manual of Surveying Instructions (2009), Sec. 6-35

Local Surveyor Testimony

The testimony and records of local surveyors who identified original monuments before their destruction are among the most reliable forms of collateral evidence:

"The testimony or records of local surveyors who have identified the original monument prior to its destruction, or who have reasonably applied the good faith location rule, or who have marked the corners of legal subdivisions according to the prevailing law using the accuracy standards for the time and locale, is often considered reliable collateral evidence." -- BLM, Manual of Surveying Instructions (2009), Sec. 6-6

Fences, Roads, and Use Lines

Physical features such as fences, roads, drainage ditches, and timber cutting lines may provide evidence of the original survey lines when they were placed with due regard to the original corners:

"A property corner or a use or occupancy position should exercise a regular control upon the retracement only when it was placed with due regard to the location of the original survey, or agreement is so close as to constitute the best available evidence." -- BLM, Manual of Surveying Instructions (2009), Sec. 6-42

Order of Procedure for PLSS Retracement#

The retracement of a township or section follows a systematic order:

Step 1: Research

Before entering the field, the surveyor obtains and studies:

• The official plat and field notes of the original survey
• The plats and field notes of any prior resurveys
• Records of local surveys in the area
• County records showing disposals and patents
• Available testimony and historical information

Step 2: Retracement of Control

The surveyor establishes a framework of identified corners by retracing the controlling lines:

1. Township exteriors -- locate and verify the township corners and section corners on the township boundaries.
2. Standard parallels and guide meridians -- verify the corners on any controlling boundary lines.
3. Interior section lines -- retrace section lines to locate interior section corners.

Step 3: Classification of Corners

Each corner is classified as existent, obliterated, or lost based on the evidence found. Existent and obliterated corners are accepted as fixed points.

Step 4: Restoration of Lost Corners

Lost corners are restored using the appropriate method of proportionate measurement, working from the framework of identified corners. Section corners are restored before quarter-section corners.

"Existing original corners shall not be disturbed. Consequently, discrepancies between the retracement measurements and the measurements shown in the record have no effect beyond the accepted corners." -- BLM, Manual of Surveying Instructions (2009), Sec. 7-5

Step 5: Subdivision of Sections

Once the section boundaries are established, the surveyor subdivides the sections by connecting quarter-section corners to determine the center of section and the quarter-quarter section boundaries.

Step 6: Documentation

The surveyor documents all evidence found, all decisions made, and all computations performed. This record is essential for the defense of the survey and for future retracement efforts.

Hierarchy of Control in Restoration#

Within proportionate measurement:

"Relative to proportionate measurement in order to harmonize the restorative process with the methods of the original survey, the principle of the precedence of one line over another of less original importance is recognized, thus limiting the control." -- BLM, Manual of Surveying Instructions (2009), Sec. 7-7

Key Takeaways#

• The retracing surveyor's duty is to recover the original survey, not to create a new one or correct the original. The purpose is to determine where corners were established, not where they should have been.
• Corners are classified as existent (recoverable from physical evidence), obliterated (recoverable from testimony or records), or lost (restorable only by proportionate measurement). A corner must not be declared lost until every means of recovery is exhausted.
• Single proportionate measurement restores lost corners on a line between two identified corners. Double proportionate measurement restores lost corners at the intersection of two lines using four controlling corners.
• All proportionate measurement uses cardinal equivalents -- the north-south and east-west components of distances, not the full measured distances along non-cardinal lines.
• Collateral evidence (good faith locations, local surveys, fences, roads) may help recover obliterated corners when evaluated in the context of the original survey record.
• The field notes and plat of the original survey are the primary record. They are presumed correct unless proven otherwise by a preponderance of the evidence.
• Retracement proceeds from larger control to smaller: standard parallels, then township exteriors, then section corners, then quarter-section corners, then sixteenth-section corners.

References#

1. U.S. Department of the Interior, Bureau of Land Management. Manual of Surveying Instructions (2009). Chapter V: Principles of Resurveys, Secs. 5-1 through 5-77. Chapter VI: Resurveys and Evidence, Secs. 6-1 through 6-77. Chapter VII: Restoration of Lost Corners, Secs. 7-1 through 7-57.
2. Act of February 11, 1805 (2 Stat. 313; 43 U.S.C. 752).
3. U.S. Department of the Interior, Bureau of Land Management. Restoration of Lost or Obliterated Corners and Subdivision of Sections. Manual Supplement.
4. Robillard, W.G., Wilson, D.A., & Brown, C.M. Brown's Boundary Control and Legal Principles (7th Ed.). John Wiley & Sons, 2014. Chapter 18.
5. Robillard, W.G. & Wilson, D.A. Evidence and Procedures for Boundary Location (6th Ed.). John Wiley & Sons, 2011. Chapters 8--9.