SURVEYS of the PUBLIC LANDS (PLSS) (The Big Picture)
SURVEYS OF THE PUBLIC LANDS (PLSS) (The Big Picture)
James A. Coan Sr., P.L.S.
INTRODUCTION
The term “Public Lands” is applied broadly to the areas that have been subject to administration, surveys, and transfer of title to private owners under the public lands laws of the Untied States since 1785
INTRODUCTION
Thirty states including Alaska, constitute the public land survey states which have been, or will be subdivided into rectangular tracts. INTRODUCTION
The area of these states represents approximately 72% of the United States.
According to the Land ordinance of May 20, 1785 the land was to be surveyed before it was sold
THE GENERAL SCHEME
According to the Manual of Surveying Instructions the law provides that:
1)The public lands of the United States shall be divided by lines intersecting true north and south lines at right angles so as to form townships six miles square.
THE GENERAL SCHEME
2) The townships shall be marked with progressive numbering from the beginning.
3) The townships shall be subdivided into 36 sections, each one mile square and containing 640 acres as near as may be THE GENERAL SCHEME
4) Sections shall be numbered, respectively, beginning with the number 1 in the northeast section and proceeding west and east alternately through the township with progressive numbers to and including 36
THE PUBLIC LAND STATES
INSTRUCTIONS FOR SURVEYS OF THE PUBLIC LANDS
The United States Public Land Survey System (PLSS) was inaugurated in 1785, and the territory that is now eastern Ohio serves as the test area. This area is known as the “The Old Seven Ranges” INSTRUCTIONS FOR SURVEYS OF THE PUBLIC LANDS
Sets of instructions for surveys began to be issued in 1784.
The first manual of instructions were issued in
1855. Later manuals were issued in 1881, 1890,
1894, 1902, 1930, 1947, 1973, and 2009
MEASUREMENTS USED IN THE PLSS
Distances given in the instructions are in chains and Links.
The particular chain that is used is the Gunter’s chain. GUNTER’S CHAIN
MEASUREMENTS USED IN THE PLSS
One chain = 100 links = 66 feet, 1 link = 0.66 feet
80 chains = 1 mile 10 square chains = 1 Acre
1 chain = 4 rods,
1 Rod = 1 Pole = 1 Perch = 16 ½ feet
MEASUREMENTS USED IN THE PLSS
Metric Conversions, US Survey Foot 1 Meter = 39.37 inches (exact) 1 US Survey Foot = 0.3048006096… meter 1 link = 0.2011684023… meter 1 meter = 3.28083333… US Survey Foot 1 acre = 0.40468726099… hectare (1 hectare = 10,000 m2) MEASUREMENTS USED IN THE PLSS
Metric Conversions, International Foot (SI) 1 inch = 25.4 millimeters (exact) 1 SI Foot = 0.3048 meters (exact) 1 meter = 3.2808398950 Si Foot
INITIAL POINT
As settlers moved westward, in each area where a substantial amount of surveying was needed, an initial point was established within the region to be surveyed
INITIAL POINT
The initial point for Washington and Oregon was set just west of what is now downtown Portland Oregon. This initial point is known as the “Willamette Stone” WILLAMETTE STONE
PRINCIPAL MERIDIANS
From each initial point, a true north – south line called a “Principal Meridian” was run to the limits of the area to be surveyed.
PRINCIPAL MERIDIANS
In Washington and Oregon this principal meridian is known as the “Willamette Meridian” (WM) and runs north to Puget Sound and south to the California border
Monuments are placed every 40 chains along the Principal Meridian BASELINES
From the initial point a base line was extended on a true parallel of Latitude, east and west to the limits of the area to be surveyed and monuments placed every 40 chains
BASELINES
Base lines, being lines of Latitude, are curved lines known as “Rhumb Lines”
The base line for Washington and Oregon begins at the initial point. It extends West to the Pacific Ocean and East to the Idaho boarder
BASELINES
According to the 1973 manual There are three ways to layout a baseline on a true parallel of latitude, they are
1)Solar Method 2) Tangent Method 3) Secant Method SOLAR METHOD
An observation is made on the sun to determine the direction of astronomic north. A right angle is then turned and a line is run for 40 chains. After a monument is placed the process is repeated.
SOLAR METHOD
Because meridians converge, each time a right angle is turned there will be a slight change in direction every ½ mile (40 chains)
The series of lines so established will closely approach a true parallel of Latitude.
PARALLEL OF LATITUDE SOLAR METHOD TANGENT METHOD
The Tangent method for determination of the true latitude consist of establishing the true meridian at the point of beginning, from which a horizontal angle of 90° is turned east or west as required.
TANGENT METHOD
The tangent is projected for six (6) miles in a straight line, and as the measurements are completed for each corner, proper offsets are measured north from the tangent line to the parallel of latitude, and the corners are established.
TANGENT METHOD
At the point of beginning the tangent line bears east or west, but as the tangent line is continued the deviation to the south increases. PARALLEL OF LATITUDE, TANGENT METHOD
PARALLEL OF LATITUDE 45°34'30" N CHAINS OFFSET AZIMUTH ON IN OF TANGENT LINKS TANGENT 00EAST 40 <1 S 89°59.1' 80 1 E 120 2 S 89°58.2' 160 4 E 200 6.5 S 89°57.3' 240 9 E 280 12.5 S 89°56.4' 320 16.5 E 360 20.5 S 89°55.6' 400 25.5 E 440 31 S 89°54.7' 480 37 E
TANGENT METHOD
Offsets from the tangent can be found in
standard field tables
STANDARD TANGENT FIELD TABLES SECANT METHOD
The designated secant is a great circle which cuts the parallel of latitude at the first and fifth mile corners, and is tangent to an imaginary latitude curve at the third mile point.
SECANT METHOD
From the point of beginning the secant line has a northeasterly or northwesterly bearing; at the third mile corner the secant bears east or west, and from the third to the six mile corners the secant bears southeasterly or southwesterly
SECANT METHOD
The secant method of determining a true latitude curve consist of establishing a true meridian south of the beginning corner a measured distance taken from tables, from this meridian the proper horizontal angle, as taken from the table, is turned to the northeast or northwest to define the secant. SECANT METHOD
From the point of beginning to the first mile, and from the fifth mile to the sixth mile the secant is south of the parallel of latitude. From the first mile to the fifth mile the secant lies north of the parallel of latitude.
SECANT METHOD
The secant is projected for six miles in a straight line, and as the measurements are completed for each corner point, proper offsets are measured, north or south , from the secant to the parallel and the proper corners are set.
PARALLEL OF LATITUDE, SECANT METHOD PARALLEL OF LATITUDE, SECANT METHOD
PARALLEL OF LATITUDE 45°34’30" N
CHAINS ON SECANT OFFSET IN LINKS AZIMUTH OF SECANT
05N 89° 57.3' E
40 2
80 0 N 89° 58.2' E
120 2
160 3 N 89° 59.1' E
200 4
240 4 EAST - WEST
280 4
320 3 S 89° 59.1' E
360 2
400 0 S 89° 58.2' E
440 2
480 5 S 89° 57.3' E
SECANT METHOD
Offsets from the secant can be found in standard field tables
It should be noted that the 2009 manual does not mention any of the above methods, it simples says;
“The determination of the alignment of the true Latitudinal curve process is described in the record” (section 3-11, 2009 manual) STANDARD SECANT FIELD TABLES
STANDARD PARALLELS
Standard Parallels, which are also called correction lines, are extended east and west from the principal meridian, at intervals of 24 miles north and south of the base line in the manner prescribed for the survey of the base line.
STANDARD PARALLELS
When standard parallels, previously run at intervals more than 24 miles, and conditions require additional standard lines, an intermediate correction line is established to which a local name may be given, such as “Fifth Auxiliary Standard Parallel”. STANDARD PARALLELS
In Washington, standard parallels are every 24 miles apart.
In Oregon, standard parallels are every 30 miles apart.
GUIDE MERIDIANS
Guide Meridians are extended north from the baseline, or standard parallels , at intervals of 24 miles east and west from the principal meridian, in the manner prescribed for running the principal meridian.
GUIDE MERIDIANS
The guide meridians are terminated at the points of intersection with the standard parallels. GUIDE MERIDIANS
The guide meridian is projected on the true meridian and the fractional measurements are placed in the last half mile
COVERGENCE OF MERIDIANS
The angular amount by which two meridians converge is a function of latitude, and the distance between meridians.
COVERGENCE OF MERIDIANS
The convergence can be computed
using standard field Table 11, and
Table 26 COVERGENCE OF MERIDIANS
COVERGENCE OF MERIDIANS
Angle Convergence Distance Convergence
COVERGENCE OF MERIDIANS QUADRANGLES
The area between the base line and the first standard parallel, and the principal meridian and the first guide meridian is known as a quadrangle. The dimension of a quadrangle is 24 miles x 24 miles.
QUADRANGLES
This is the same area between successive standard parallels and guide meridians
QUADRANGLES
Once the quadrangle is surveyed into
townships. Each township is 480 chains east, west, and 480 chains north, south
(6 miles x 6 miles not counting for convergence ) TOWNSHIP EXTERIORS
The division of quadrangles into townships is accomplished by running range lines (meridional lines), and township lines (latitudinal lines)
TOWNSHIP EXTERIORS
Range lines are astronomic meridians beginning at a standard corner on a base line or standard parallel at 6 mile (480 chain) intervals, and running north to close on the next standard parallel north.
TOWNSHIP EXTERIORS Township lines are east – west lines that connect township corners previously established at intervals of 6 miles (480 chains) on a principal meridian, guide meridian, or range line.
The 6 mile square is known as a Township 1st STANDARD PARALLEL NORTH
CCCC CC CC
10 20 36
9 19 33 35 8 18 32 34
7 17 31
6 16 28 30 5 15 27 29
4 14 26 PRINCIPAL MERIDIAN
3 13 23 25 GUIDE MERIDIANEAST st
2 12 22 24 1
1 11 21
SCSC SC SC SC
BASE LINE
TOWNSHIP EXTERIORS
According to the Manual of Surveying Instructions the regular order of Township Exteriors are as follows.
TOWNSHIP EXTERIORS
The south and east boundaries of a township are normally the governing lines of the Sub-divisional survey. TOWNSHIP EXTERIORS
Whenever practicable the township exteriors are
surveyed successively through a quadrangle in
ranges of townships, beginning with the township on the south.
TOWNSHIP EXTERIORS
The meridianal township boundaries have precedence in the order of the survey and are run from south to north on true meridians.
TOWNSHIP EXTERIORS
Quarter section and section corners are established alternately at a permanent corner in proper position.
A meridional exterior is terminated at the point of intersection with a standard parallel. TOWNSHIP EXTERIORS
Excess or deficiency in measurement is placed in .the north half mile. A closing corner is established at the point of intersection with the standard parallel.
TOWNSHIP EXTERIORS
The standard parallel is retraced between the nearest standard corners to the east and west to find the exact alignment, and the distance to the nearest corner is measured and recorded.
TOWNSHIP EXTERIORS
In order to complete the exteriors of a Township, and if defective conditions are not encountered, the latitudinal boundary is run connecting the objective township corners. TOWNSHIP EXTERIORS
Corners are established from east to west along the latitudinal curve connecting the township corners, at intervals of 40 chains and at intersections with meanderable bodies of water, marking the true line.
TOWNSHIP EXTERIORS
By this procedure, the excess or deficiency in measurement is incorporated in the west half mile. And double sets of corners are avoided when unnecessary.
TOWNSHIP EXTERIORS
When lines are run by random and true method, the bearing of the true line is calculated from the falling of the random. The falling is the distance, on the normal, by which a line falls to the right or left of an object corner. TOWNSHIP EXTERIORS
Where both meridional boundaries are new lines or where both have been previously established, a latitudinal random line is run from east to west.
TOWNSHIP EXTERIORS
Regular quarter and section corners are set at 40 chains and the fractional measurement is placed in the last half mile west.
TOWNSHIP EXTERIORS
The temporary points on the random line are replaced by permanent corners on the true line.
The allowable deviation in bearing of a township is 00°14’00” from cardinal. 1st STANDARD PARALLEL NORTH
CCCC CC CC
10 20 36
9 19 33 35 8 18 32 34
7 17 31
6 16 28 30 5 15 27 29
4 14 26 PRINCIPAL MERIDIAN
3 13 23 25 GUIDE MERIDIANEAST st
2 12 22 24 1
1 11 21
SCSC SC SC SC
BASE LINE
DESIGNATION OF TOWNSHIPS
A township is identified by a unique description based on the principal meridian governing it.
DESIGNATION OF TOWNSHIPS
North and south columns of townships are called RANGES, and are numbered in consecutive order east and west of the principal meridian DESIGNATION OF TOWNSHIPS
East and West rows of townships are called TOWNSHIPS and are numbered consecutive north and south of the baseline
DESIGNATION OF TOWNSHIPS
An individual township is identified by its
number north or south of the baseline,
followed by the number east or west of the principal meridian.
DESIGNATION OF TOWNSHIPS
An example is “ Township 23 North, Range 5 East, Willamette Meridian. Abbreviated T 23 N, R 5 E, WM DESIGNATION OF TOWNSHIPS
SUBDIVISION OF TOWNSHIPS INTO SECTIONS
Sections are numbered from 1 to 36, beginning in the northeast corner of a township with section 1, and ending with section 36 in the southeast corner of the township.
SUBDIVISION OF TOWNSHIPS INTO SECTIONS
Meridianal section lines have precedence in the order of survey. They are initiated at the section corners on the south boundary of the township and are run north parallel with the east boundary of the township. SUBDIVISION OF TOWNSHIPS INTO SECTIONS
Meridianal section lines are numbered from the east and are surveyed successively in the same order
SUBDIVISION OF TOWNSHIPS INTO SECTIONS
If the east boundary of the township is within limits, but has been found by retracement to be imperfect in alignment, the meridianal section line will be run parallel with the mean course.
SUBDIVISION OF TOWNSHIPS INTO SECTIONS
Regular quarter section and section corners are set at 40 and 80 chains as far as the Northern-most interior section corner. SUBDIVISION OF TOWNSHIPS INTO SECTIONS
A meridianal section line is not continued north beyond a section corner until after the connecting latitudinal sectional line has been surveyed.
SUBDIVISION OF TOWNSHIPS INTO SECTIONS
The last mile of a meridianal section line is run as a random line with a temporary quarter corner set at 40 chains. The falling of the random line is corrected and the line is corrected to the true line. But only is if can stay in limits
SUBDIVISION OF TOWNSHIPS INTO SECTIONS
When a meridianal section line is run to a standard parallel, a closing corner is set at the standard parallel.
The error of the township is placed in the north half mile. SUBDIVISION OF TOWNSHIPS INTO SECTIONS
The latitudinal section lines, except the west range of sections, are normally run from west to east parallel with the south boundary of the township on a random line setting a temporary quarter corner at 40 chains.
SUBDIVISION OF TOWNSHIPS INTO SECTIONS
The line is then corrected and a quarter corner is set in it’s proper place.
SUBDIVISION OF TOWNSHIPS INTO SECTIONS
In the west range of sections the latitudinal section is run on a random line from east to west placing a quarter corner at 40 chains from the east section line. SUBDIVISION OF TOWNSHIPS INTO SECTIONS
The random is then corrected back on the true latitude.
The error of the township is placed in the west most half mile.
SUBDIVISION OF TOWNSHIPS
Regular Sections
Reality DEFINITIONS
ALIQUOT PART
Aliquot part – Aliquot is a French term meaning “equal with no remainder”. It is used to refer to any of the normal subdivision of section.
DEFINITIONS
LOT (Government Lot)
Lot – a non-aliquot subdivision of a section. Based on the previous definition, this parcel of land would not be equal in the same way an aliquot part would be.
SUBDIVISION OF SECTIONS
Sections are divided into quarter sections by running straight lines between opposite quarter section corners. This will divide the section into four aliquot parts. SUBDIVISION OF SECTIONS
It must be noted that the section is NOT divided evenly by area, but divided by aliquot parts, and Government Lots
SUBDIVISION OF SECTIONS
If a quarter section is to be divided further, lines are run between quarter-quarter section corners in the same manner the section was divided into quarter sections.
SUBDIVISION OF SECTIONS
Under the general laws, broadly, the unit of administration is the quarter-quarter section of about 40 acres. SUBDIVISION OF SECTIONS
The private surveyor is usually responsible for subdividing sections in the field.
SUBDIVISION OF SECTIONS BY PROTRACTION
Upon the plat of all regular sections the boundaries of the quarter section are shown by broken straight lines connection the opposite quarter corners.
SUBDIVISION OF SECTIONS BY PROTRACTION
The sections bordering the north and west boundaries of normal townships , except section 6, are further subdivided by protraction into parts containing two regular half quarter sections and four lots. SUBDIVISION OF SECTIONS BY PROTRACTION
Section 6 has lots protracted against the north and west boundaries , and so contains two regular half quarter section, one quarter- quarter section, one quarter section, and seven lots.
SUBDIVISION OF SECTIONS BY PROTRACTION
Sections that are invaded by meanderable bodies of water, or by approved claims at variance with the regular legal subdivisions, are subdivided by protraction into regular and fractional parts as may be necessary.
SUBDIVISION OF SECTIONS BY PROTRACTION SUBDIVISION OF SECTIONS BY PROTRACTION
GOVERNMENT LOTS
Sections are protracted so as to provide a maximum number of aliquot parts (160, 80,and 40 acre units) or regular subdivision of section. The remaining areas in these sections is shown as lots, commonly referred to as “Government Lots”.
GOVERNMENT LOTS
Boundaries of lots usually follow the quarter section and quarter quarter section lines, but extreme lengths or narrow widths are avoided, as are areas of fewer than 10 acres or more than 50 acres. GOVERNMENT LOTS
FRACTIONAL SECTIONS
DEFINITION – Fractional Section – A section with one or more subdivisions of less than 40 acres due to one or more controlling corners never being set.
FRACTIONAL SECTIONS
This usually occurs due to incomplete sections, meanderable bodies of water, or invasion of non-rectangular entities FRACTIONAL SECTIONS
Regarding fractional sections, the LAW says “The subdivision lines will be run in cardinal directions”
FRACTIONAL SECTIONS
The law presumed that the section lines were actually run cardinally. Since a resurvey will almost always find those lines to be other than cardinal, some adjustment must be made to allow you to protect the plat, and patents
(see 2009 manual 3-120)
FRACTIONAL SECTIONS There are three basic methods to perform this process, with specific applications for each one. They are:
1) Arithmetic Mean 2) Weighted Mean 3) Parallel Lines FRACTIONAL SECTIONS
Arithmetic Mean
An arithmetic mean (or average) is used to distribute any differences between the controlling section lines in an equitable manner.
FRACTIONAL SECTIONS
This method is best applied when the mid- section line is in the center, and the controlling section lines are essentially the same length.
h
c
5
4
.
7
2
E
’
2
0
°
0
0 N 00°04’W
N 00°10’W 27.50 ch N
FRACTIONAL SECTIONS
Weighted Mean
In most applications, the weighted mean is a far better approach. It considers the length of the controlling section lines in the meaning process. FRACTIONAL SECTIONS
Weighted Mean Weighted means are especially needed when the controlling section lines vary greatly in length. Line Controlling Line Controlling Weighted mean Line
FRACTIONAL SECTIONS
Weighted Mean Computation Tip
To compute a weighted mean using a COGO routine, run a traverse in the program using all the controlling lines as if they are connected end to end.
FRACTIONAL SECTIONS Weighted Mean Computation Tip
Inverse back to the beginning point and the resulting bearing will be a weighted mean FRACTIONAL SECTIONS
Parallel Lines
There are some fractional section situations where you do not have an opposite section line to control a mean.
FRACTIONAL SECTIONS Parallel Lines In this case parallel lines are your only equitable solution.
e ak L 9 8 40.00 18.76 40.00 31.25 40.00
17 16
MEANDERING
The traverse of the margin of a permanent natural body of water is termed a meander line. All navigable bodies of water and other important rivers and lakes are segregated from the public lands by the mean high water elevation. MEANDERING
In the original surveys, meander lines are run for the purpose of ascertaining the quantity of land remaining after the segregation of the water area.
MEANDERING
Monuments (meander corners) are placed where meander lines intersect with section, township, or range lines.
MEANDERING
Low Water
The low water mark is the point to which a river or other body of water recedes, under ordinary conditions, at its lowest stage. MEANDERING
High Water
The high water mark is the line which the water impresses on the soil by covering it for sufficient periods to deprive it of vegetation.
MEANDERING
Shore Lands
The shore is the space between the margin of high water and low water (Alabama v. Georgia, 64 U.S. 505 (1859))
MEANDERING
MEANDER LINES ARE NOT INTENDED TO
BE BOUNDARY LINES MEANDERING Rivers
Navigable rivers and bayous, as well as all rivers not navigable whose right angle width is 3 chains or more are meandered on both banks, at the ordinary mean high water mark, by taking the general course and distances of their sinuosities.
MEANDERING
Rivers
Rivers not classed as navigable are not meandered above the point where the average right angle width is less than 3 chains, except when duly authorized.
MEANDERING
Lakes
All lakes of the area of 50 acres or more are to be meandered. MEANDERING Lakes In the case of lakes which are located entirely within a section, a quarter section line, if one crosses the lake, a theoretical course is run from one quarter corner to the opposite quarter corner, to the margin of the lake, and the distance is measured. At the point determined a “special meander corner” is established.
MEANDERING Lakes
If a meanderable lake falls entirely within a quarter section, an “auxiliary meander corner”is established at some suitable point on its margin, and a connection line is run from the established monument to a regular corner on the section boundary.
MEANDERING Islands Every island above the mean high water elevation of a meanderable body of water , except islands formed in navigable bodies of water after the date of admission of a state into the Union, is located by triangulation or direct measurement or other suitable process, and is meandered and shown upon the official plat. MEANDERING Islands Even though the United States has parted with its title to the adjoining mainland, an island in a meandered body of water, navigable or non- navigable, in continuous existence since the date of admission of the State into the Union, and omitted from the original survey, remains public land of the United States.
MONUMENTS
The law provides that the original corners established during the process of surveying shall forever remain fixed in position, even disregarding technical errors which may have passed undetected before acceptance of the survey.
(See 2009 Manual, Section 4-2)
MONUMENTS
A knowledge of monumentation employed during the execution of the public land surveys is an indispensable attribute for the present day surveyor. MONUMENTS
To retrace the footsteps of the original surveyors, the present day surveyor must have a good understanding of the monuments and references used in the region concerned.
MONUMENTS
Accessories
Before discussing the topic of monuments and their accessories a few definitions should be given.
MONUMENTS
“Blaze”
A blaze is an artificial mark that is ordinarily made upon on a tree about chest height. MONUMENTS
Hack
A hack is an artificial mark that is made on a tree about chest height which leaves a horizontal mark cut into the tree.
MONUMENTS
Accessory
An accessory is an object utilized to reference the position of a corner monument, such as trees, natural objects, permanent improvements, reference monuments, stone mounds, etc.
MONUMENTS Bearing Trees
Bearing trees (reference trees) should be marked on the side facing the monument they are referencing and are inscribed with the letters and figures appropriate for the corner concerned MONUMENT ACCESSORIES
MONUMENT ACCESSORIES Mound of Stone A mound of stone is a corner accessory: consists of at least five stones and has at least a 2 foot square base and 1.5 feet high. The position of the accessory mound is placed with its nearest point 6 inches from the monument.
MONUMENT ACCESSORIES
Pit
A pit is a hole, which is specified to be 18 inches square and 12 inches deep, with the nearest side 3 feet from the monument. The pit is oriented with a side (not a corner) toward the monument. MONUMENT ACCESSORIES Line Tree
A line tree is a tree on a survey line such as a section line. The line tree is marked with either a blaze, a hack or both to help identify the position of the line. When retracing surveyors find a line tree it is treated as a monument.
MONUMENT ACCESSORIES
Memorial
A memorial is any durable object that serves to identify the location of a monument. Articles such as glass, stones with an “X” marked in them, a charred stake, charcoal, metal, can serve as memorials. They are placed along side the monument
MONUMENTS Corner A corner is at the end of a boundary line or at a change in direction of a boundary line. A corner may also be placed along a line where a third party may tie in or reference in a senior line. To be controlling, a corner does not have to be monumented MONUMENTS
Monument
A monument is a physical manifestation set at or near a corner. Monuments can fall into two categories: natural and artificial. Natural monuments will control over artificial if they are in conflict with one another.
MONUMENTS
Quarter Corners Quarter corners are placed to divide the section into quarters. They are usually set equidistant from two section corners, except in the northern tier or western range of a township where they are placed 40 chains from the south or east section corners.
MONUMENTS Section Corner
Section corners are placed at the four corners of a section. Interior section corners are placed at 80 chains. Section corners places on the north tier or west range of a township close on the township or range line. MONUMENTS
Standard Section Corners Standard corners are measured along standard parallels every 80 chains. Because standard parallels are correction lines the standard corners only govern the sections and townships to the north and are marked “S.C.”
MONUMENTS Closing Corners
Closing corners close on standard parallels from the south. Because of the convergence of meridians the distance between closing corners are less than 80 chains and only govern the top tier of sections to the south of the standard parallel. Closing corners are marked “C.C.” North quarter corners are not set between closing corners.
MONUMENTS MONUMENTS Closing Corners
Closing corners can also be found
anywhere in a township where a junior line
closes on a senior line, such as on a
completion survey.
MONUMENTS Closing Corners Completion Survey
MONUMENTS
Witness Corner
A witness corner is a monumented point usually on a line of a survey and near a corner. It is established only in situations where it is impracticable to occupy the site of a corner. MONUMENTS
Reference Monument
A reference monument is an accessory and is employed in situations where the site of a corner cannot be established or where the monument would be liable to destruction, and bearing trees or a nearby bearing object are not available.
MONUMENTS
Witness Point
A witness point is a monumented station on the line of the survey that is used to perpetuate an important location more or less remote from and without special relation to any regular corner.
MONUMENTS
Meander Corners
Meander corners are placed where meander lines intersect with section, township, or range lines RESTORING LOST OR OBLITERATED CORNERS Definitions
Corner – A position on the surface of the earth.
Existing Corner – A point which can be identified in it’s original position based on evidence, testimony, or both.
RESTORING LOST OR OBLITERATED CORNERS Definitions
Obliterated Corner – A point at which no evidence of the original monument or accessories exist, but whose position has been perpetuated by the acts of testimony of a witness, competent surveyor, local authorities, or the interested land owner. RESTORING LOST OR OBLITERATED CORNERS Definitions
Lost Corner – A point whose position cannot be determined beyond a reasonable doubt and must be set by a mathematical solution from one or more interdependent corners.
RESTORING LOST CORNERS Single Point Control
The method of single point control is simply the running of “record” bearing and distance. It would be used where the line in the survey you are retracing terminated at your lost corner.
RESTORING LOST CORNERS Single Point Control Some examples of this would be Meander corner where line was not run across the water Stubbed out section 1/4 , or 1/16th corner, or witness corner Other corners stubbed out in the record RESTORING LOST CORNERS Single Point Control
SECTION 10 SECTION 11
FOUND FOUND FOUND
S
0
1
°
5
6
’ Record B & D E SECTION 14 2
9
.
5
2
SECTION 15 c h LOST MC
RIVER
RESTORING LOST CORNERS Two Point Control
Two point control deals with a lost corners where the line was run in two directions only, roughly 90° to each other. An example would be where a township corner only applies to one Township or only one Section.
RESTORING LOST CORNERS Two Point Control
The process involves the running of “record” bearing and distance reduced to their cardinal equivalents from the two found corners, setting “temps.” and then making cardinal moves from those points to set the lost corner. RESTORING LOST CORNERS Double Point Control
Unsurveyed Lands
LOST SECT. FOUND ¼ COR. S 89° 56’ E 40.19 ch. COR.
. h c
3 2 Record B & D . 0 4
E ’ SECTION 15 5 1 ° 0 1 N FOUND ¼ COR. Remember, Reduce to Cardinal!
RESTORING LOST CORNERS
Three Point Control
Where a township or section corner is lost, and the line was never established in one direction, triple point control will be used
RESTORINGRESTORING LOST LOST CORNERS CORNERS Three Point Control
. It requires a single proportion, using cardinal equivalents on the line with two controlling corners, and a record bearing and distance from the third controlling corner. RESTORING LOST CORNERS Three Point Control
Cardinal moves are then made from these
positions to fix the lost corner point.
RESTORING LOST CORNERS Three Point Control Remember, Reduce to Cardinal!
FOUND ¼ COR. Proportion SECTION 11
E
. Unsurveyed ’
H 5
0 C Use Record Lands °
2
1
1
0 .
0
N 4 N 82° 39’ W FOUND ¼ COR. LOST SECTION N CORNER. 4 35.95 CH. 0 0 2 . 8 ° 3 1 0 C ’ H W SECTION 14 Proportion . FOUND ¼ COR.
RESTORING LOST CORNERS Single Proportions
The single proportion is applied to lost corners along a line. The history of the survey, as shown in the record, will show you how the point was originally established. RESTORING LOST CORNERS Single Proportions
A single proportion “spreads” any excess or deficiency along the line between two found corners in the same ratio as indicated by the record.
RESTORING LOST CORNERS Single Proportions
The most common uses for single proportions are Quarter corners, All standard corners All corners on township and range lines, except township corners, Non-rectangular parcel corners on a straight line in the record
RESTORING LOST CORNERS Single Proportions
LOST CORNER
FOUND R = S 89°56’W 80.22 CH FOUND CORNER CORNER M = S 89°21’W 80.91 CH
SINGLE PROPORTION RESTORING LOST CORNERS Single Proportions
Single Proportions sometimes cannot follow the regular rule when the record shows a bearing break at the lost corner. A different procedure must be used in this situation.
RESTORING LOST CORNERS Single Proportions
Section 7-52 of the 2009 Manual describes a system for this process which says to use a single proportion in the direction of the line but a compass rule adjustment in the other direction.
RESTORING LOST CORNERS Single Proportions
When proportioning along the line,
remember to Reduce to Cardinal! RESTORING LOST CORNERS
LOST CORNER
R= CH N8 05 8° 41. 25 ’W ’W °01 40 89 .22 =S C R M=N 89°59’W 81.33 CH H
R=N 89°43’W 81.25 CH FOUND FOUND CORNER CORNER SINGLE PROPORTION WITH BEARING BREAK
Remember to Reduce to Cardinal!
RESTORING LOST CORNERS Double Proportionate Measurement
Double proportions are used for lost corners common to four townships, as well as four sections in the interior of a township
RESTORING LOST CORNERS Double Proportionate Measurement
The term “double proportionate measurement” is applied to new measurements made between four known corners, RESTORING LOST CORNERS Double Proportionate Measurement
two each on intersecting meridianal and latitudinal lines, for the purpose of relating the intersection to both.
RESTORING LOST CORNERS
Double Proportionate Measurement
Lengths of proportional lines are comparable only when reduced to their cardinal equivalents.
RESTORING LOST CORNERS
Double Proportionate Measurements
W
’
Section 16 1 Section 15
2
°
5
0
0
.
0
0
4 N
N 89°55’W S 89°02’W 40.00 40.00
0 0 . 0 Section 218 Section 22
E ’ 7 3 ° 1 0
N Found Corner
Remember to Lost Corner Reduce to Cardinal GRANT BOUNDARY ADJUSTMENTS
The Grant Boundary method is used to set lost corners on most of the non-rectangular entities within the PLSS. It involves the comparison of distances between the record and the measured to establish a ratio for adjustments
GRANT BOUNDARY ADJUSTMENTS
Then a rotation is established between the two surveys for bearings. It’s purpose is to preserve the angular relationship at the lost corners, and to adjust the distance at the same ratio through each lost corner.
GRANT BOUNDARY ADJUSTMENTS
The steps for this method are as follows 1)Reduce the record bearing and distances to the 2) total difference in latitude and departure and 3) inverse to determine the direction and length 4) between the identified points. GRANT BOUNDARY ADJUSTMENTS
2) Determine the actual bearing and distance between the same identified points
3) The difference between the bearings in step one and two above will determine the amount and direction of rotation of the record bearings of each intermediate course.
GRANT BOUNDARY ADJUSTMENTS
4) The ratio of the lengths computed in steps one and two above will be applied to the record length of each intermediate course.
5) Search again before re-setting lost corners.
GRANT BOUNDARY ADJUSTMENTS
Found Corner
Lost Corner
1°25’W N S8 67 1.29 °1 6 4 5’W ’W 9.7 30 2 7° 1 N 87°35 4 .6 ’W S 58 51.23 N N 8 5°36’5 2 6”W 4 6 274. ° 23ch 9 1 (18, . 5 099.18 5 ’) (R) 6 ’W N 87°10’35”W 1 8,049.25’ (M)
Rotation Angle = 01°33’39”: Ratio = 0.9972413 MEANDER LINES ADJUSTMENTS Non-riparian Meander Lines
The purpose of a meander line was to run the approximate boundaries of a limiting feature such as a river or lake.
MEANDER LINES ADJUSTMENTS
Non-riparian Meander Lines
Meander lines were never intended to be a boundary line and therefore was rarely monumented.
MEANDER LINES ADJUSTMENTS Non-riparian Meander Lines
However, under certain conditions they can become a boundary.
Also in the State of Washington, under State Law, and under certain conditions, Meander Lines can become a boundary line. MEANDER LINES ADJUSTMENTS Non-riparian Meander Lines
Meander lines are adjusted using the Compass rule.
C Corection S L C = total error in lats. or deps. with the sigh changed L = Total length of survey S = length of particular course
CONCLUSION
This has been an overview of the Public
Land Survey System. To become an
expert in this subject one must do much
more, in-depth studies on the subject.
CONCLUSION
This is a fascinating part of surveying and
one every surveyor working in a Public Land
state should be familiar with BIBLIOGRAPHY
Restoration of Lost Corners workshop by Dennis Mouland PLS
Lotted Section Workshop, by Dennis Mouland PLS
Land Survey Systems, by John G. McEntyre
Manual of Surveying Instructions 1973, 2009 Bureau of Land Management