Surveys of the Public Lands (PLSS) - Esri · 2011-06-28 · GUIDE MERIDIANS Guide Meridians are...

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

Thirty states including Alaska, constitute the

public land survey states which have been,

or will be subdivided into rectangular tracts.

INTRODUCTION

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


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


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)


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

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

Base lines, being lines of Latitude, are curved

lines known as “Rhumb Lines”

BASELINES

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 45°34'30" N

CHAINS ON

TANGENT

OFFSET IN

LINKS

AZIMUTH OF

TANGENT

0 0 EAST

40 <1

80 1S 89°59.1'

E

120 2

160 4S 89°58.2'

E

200 6.5

240 9S 89°57.3'

E

280 12.5

320 16.5S 89°56.4'

E

360 20.5

400 25.5S 89°55.6'

E

440 31

480 37S 89°54.7'

E

PARALLEL OF LATITUDE, TANGENT METHOD

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 METHODThe 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 45°34’30" N

CHAINS ON SECANT OFFSET IN LINKS AZIMUTH OF SECANT

0 5 N 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

PARALLEL OF LATITUDE, SECANT METHOD

Offsets from the secant can be found in

standard field tables

SECANT METHOD

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 PARALLELSWhen 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.


The convergence can be computed

using standard field Table 11, and

Table 26



AngleConvergenceDistanceConvergence


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

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 )

QUADRANGLES

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 EXTERIORSTownship 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

BASE LINE

PRIN

CIP

AL M

ER

IDIA

N

1stG

UID

E M

ER

IDIA

N E

AST

CCCCCC CC

SC SCSCSCSC

1

2

3

4

5

6

7

8

9

10

11

12

13

32

15

16

17

18

19

20

21

22

23

26

27

28

31

33

24

25

29

30

34

35

14

36

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

A meridional exterior is terminated at the point of

intersection with a standard parallel.

Quarter section and section corners are

established alternately at a permanent corner in

proper position.

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

BASE LINE

PRIN

CIP

AL M

ER

IDIA

N

1stG

UID

E M

ER

IDIA

N E

AST

CCCCCC CC

SC SCSCSCSC

1

2

3

4

5

6

7

8

9

10

11

12

13

32

15

16

17

18

19

20

21

22

23

26

27

28

31

33

24

25

29

30

34

35

14

36

DESIGNATION OF TOWNSHIPS

A township is identified by a unique description

based on the principal meridian governing it.


North and south columns of townships are

called RANGES, and are numbered in

consecutive order east and west of the principal

meridian


East and West rows of townships are called

TOWNSHIPS and are numbered consecutive

north and south of the baseline


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.


An example is “ Township 23 North, Range 5

East, Willamette Meridian. Abbreviated T 23 N,

R 5 E, WM


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.


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.


Meridianal section lines are numbered from the

east and are surveyed successively in the

same order


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.


Regular quarter section and section corners are

set at 40 and 80 chains as far as the

Northern-most interior section corner.


A meridianal section line is not continued north

beyond a section corner until after the

connecting latitudinal sectional line has been

surveyed.


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


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.


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.


The line is then corrected and a quarter corner

is set in it’s proper place.


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.


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

RegularSections

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.


It must be noted that the section is NOT divided

evenly by area, but divided by aliquot parts,

and Government Lots


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.


Under the general laws, broadly, the unit of

administration is the quarter-quarter section of

about 40 acres.


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.


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.


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.


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.



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 SECTIONSThe 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 SECTIONSThere 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.

N 0

0°10

’W 2

7.50

ch

N00

°02 ’

E27

.45

ch

N 0

0°04

’W

FRACTIONAL SECTIONSWeighted 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 means are especially needed when

the controlling section lines vary greatly in

length.

Weighted Mean

Con

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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 SECTIONSWeighted 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 SECTIONSParallel Lines

In this case parallel lines are your only

equitable solution.

31.25 40.00

40.0

0

18.

76

Lake

9

8

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

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.

Rivers

MEANDERING

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.

Rivers

MEANDERING

Lakes

All lakes of the area of 50 acres or more are to

be meandered.

MEANDERINGLakes

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.

MEANDERINGLakes

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.

MEANDERINGIslands

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.

MEANDERINGIslands

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.

MONUMENTSBearing 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

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.


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 ACCESSORIESLine 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.


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

MONUMENTSCorner

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.

MONUMENTSQuarter 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.

MONUMENTSSection 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 CornersCompletion 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.

MONUMENTSReference 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.


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.


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.



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



FOUND FOUND FOUND

LOST MC

S01°56’ E

29.52ch

Record B & D

SECTION 10 SECTION 11

SECTION 15

SECTION 14

RIVER


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.


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.


Double Point Control

SECTION 15

FOUND ¼ COR.

FOUND ¼ COR.

LOST SECT. COR.

Unsurveyed Lands

S 89° 56’ E 40.19 ch.

N10

°15’

E40

.23

ch.

Record B & D

Remember, Reduce to Cardinal!


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

RESTORING LOST CORNERSRESTORING LOST 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.


Three Point Control

Cardinal moves are then made from these

positions to fix the lost corner point.


Three Point Control

FOUND ¼ COR.

FOUND ¼ COR.

FOUND ¼ COR.

SECTION 11

SECTION 14

UnsurveyedLands

LOST SECTION CORNER.

N01

°05

’ E

40.1

2C

H.

N 82° 39’ W

35.95 CH.

N02° 10’ W

40.83C

H.

Proportion

Proportion

Use Record

Remember, Reduce to Cardinal!


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.


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.


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


Single Proportions

R = S 89°56’W 80.22 CH

M = S 89°21’W 80.91 CH

FOUNDCORNER

FOUNDCORNER

LOST CORNER

SINGLE PROPORTION

RESTORING LOST CORNERSSingle 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.


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.


When proportioning along the line,

remember to Reduce to Cardinal!


R=S89°01’W 41.05 CH R=N88°25’W 40.22 CHM=N 89°59’W 81.33 CH

R=N 89°43’W 81.25 CHFOUNDCORNER

FOUNDCORNER

LOST CORNER

SINGLE PROPORTION WITH BEARING BREAK

Remember to Reduce to Cardinal!


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



The term “double proportionate measurement” is

applied to new measurements made between

four known corners,



two each on intersecting meridianal and

latitudinal lines, for the purpose of relating the

intersection to both.



Lengths of proportional lines are comparable only

when reduced to their cardinal equivalents.


N00

°21’

W40

.05

N01

°37’

E80

.00

S 89°02’W40.00

N 89°55’W 40.00

Section 15Section 16

Section 21 Section 22

Found Corner

Lost Corner

Double Proportionate Measurements

Remember to 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


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.


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.


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.


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.


N26°15’W

49.56

N 87°35’W51.23

N67°15’W49.72

S81°25’W61.29

S47°30’W

58.61

N 85°36’56”W 274.23ch (18,099.18’) (R)N87°10’35”W 18,049.25’ (M)

Rotation Angle = 01°33’39”: Ratio = 0.9972413

Lost Corner

Found Corner

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 were never intended to be a

boundary line and therefore was rarely

monumented.

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 are adjusted using the Compass rule.

C = total error in lats. or deps. with the sigh changedL = Total length of surveyS = length of particular course

CCorection SL

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 PLSLotted Section Workshop, by Dennis Mouland PLSLand Survey Systems, by John G. McEntyreManual of Surveying Instructions 1973, 2009 Bureau of Land Management

Surveys of the Public Lands (PLSS) - Esri · 2011-06-28 · GUIDE MERIDIANS Guide Meridians are...

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