Subdivision of Fractional Sections ISPLS PDF Free Download

Course Objectives Understand the definition of a fractional section from the surveyor s viewpoint See the Federal Law on this topic, and learn how and when to apply it Learn how to compute a weighted mean bearing See how this applies to completion surveys

First; some terminology RETURNS Official reports. In cadastral survey parlance, the returns are the field notes, report and approved plat of a survey. Any measurement approved is considered a return

How did they measure those to get a return?

FIXED 3 120 The law presumes that a corner has not been fixed when: (1) the section line on each side of the corner position has not been actually run (figure 3 44) or, (2) the section line has been actually run but at least one corner on each side, on the section line at issue, has not been monumented (figure 3 45). The rule presumes that a section line has been actually run when a bearing and distance of the line is returned in the official survey record.

Fractional Section 3 119 By law a fractional section is (1) a section containing outlying areas protracted as surveyed, or (2) an invaded section in which at least one quarter section corner has not been or cannot be fixed. The method of subdivision by survey is outlined in 43 U.S.C. 752(2)(cl. 3) and 753(cls. 2 and 4). By rule the procedure for subdivision of the fractional section is to be as nearly as possible in conformity with the official survey.

Fractional Sections Dennis s definition: A section with one or more of it s controlling corners never established (Established = fixed) Established? Was a return published on the distances controlling it? Sometimes a section may not be fractional but a quarter section of it is fractional by the BLM definition Beware using fractional term just because a deed or patent uses it; fractional is a term for title issues when a parcel is less than 40 acres. This often does not trigger the survey definition of fractional. The SW1/4 of the NW1/4 of fractional Section 3, T, R, M

Sections 17, 18, and 19 are all fractional. They have no returns across the lake. Those lines were not run nor approved by the GLO. Section 20 has a fractional NW1/4. Ties to islands are not approved PLSS lines and should not be used in retracements.

Are these sections Fractional? Note the returns. These can all be subdivided normally

NOT fractional, so subdivide normally

The fact that the ¼ corners of minimum control were not set DOES NOT make these sections fractional

Federal Law on Fractional Sections Act of Feb. 11, 1805 said: Regarding fractional sections, the subdivisional lines shall be run in cardinal directions. Jared Mansfield was Surveyor General, and he immediately interpreted this law in this manner: Congress presumed the section lines were cardinal, therefore we must adjust the subdivisional lines if the section lines are found to be other than cardinal.

Mansfield s concerns

EXAMPLE: Section 17 E/W centerline What bearing? Congress addressed this in the 1805 Act. Regarding fractional sections, the subdivisional lines shall be run in cardinal directions. Mansfield immediately interpreted this to require mean bearings. We now use weighted mean or parallel lines as the facts dictate

Application of Fractional Rules Weighted Mean Bearing if: You have two or more lines to weight against; the longer lines control the mean more than the shorter. Run Parallel Lines if: You only have one sideline to which you can apply the intent of the plat. Used where no other section line exists or if the plat indicates not to spread adjustment through the entire section.

Parallel line and Weighted Mean Example

How do you compute a weighted mean? In COGO, connect all the lines you are using in the calc end to end with your measured data. Inverse between the two end points and the result is a perfectly weighted mean. B/D 2 B/D 3 B/D 1

EXAMPLE: Section 17 E/W centerline weighted mean: NE Cor S17 to N1/4 S17 = N89W 40.25 N1/4 S17 to NW Cor S17= N88W 40.33 SE Cor S17 to S1/4 S17= S89 30W 39.89 S1/4 S17 to MC S17/S20= N84W 3.18 Place these end to end in a traverse routine. Inverse for answer: N89 01 45 W

Parallel lines when nothing to mean against

Section 20: C1/4 can be set normally. Only the NW1/4 needs the special rules, after the CW and CN1/16ths are set normally. Back in

Back in Section 17, how would you set the CW1/16 th?

Intended to be parallel

The east line of the western tier of sections was intended to be parallel to the east twp bdy. And since the ¼ s of those sections are at 40 chains rather than midpoint, and since their W1/16ths are at 20 chains, then the plats intent is for the entire effect of convergence to be thrown into the western lots. So to subdivide S19 with any type of mean bearing would violate the intent of the plat!

Parallel line must be used to protect the plat

Subdivisional Corners created? Yes, but not monumented: Supreme Court has ruled they were all fixed by the plat Not synonymous terms; monument, corner, fixed Corner is a point on the surface of the earth, a location Monument is a physical object claiming to be at a corner point

Finally, Completion Surveys

Original Surveys/Extensions/Completions Original survey creates boundaries, but not all townships done in their entirety Extensions add to an incomplete twp, but not finish it Completions finish a partially surveyed township Always create jr/sr in odd places What do you mean, unsurveyable?

What do you mean, Unsurveyable? Lands not yet surveyed. Fractional section surveys for example, leave unsurveyed land within a section. The land is known to exist but the survey has either not yet been authorized or has not yet been completed. Congress did not authorize surveying of waste land that could not support agriculture

Example Extension Survey ORIGINAL EXTENSION

Example Completion Survey Cross hatching Indicates where Jr/sr is taking Place ORIGINAL Double corners Offsets All because of the Main Goals, and Rectangular limits EXTENSION COMPLETION

Completions show up in strange ways

Land Grants are senior to the PLSS

Grant declared invalid, so remaining PD must be surveyed. Note closings on both sides of line, even though it is a rejected boundary.

In reality, the record supports the fact there are two Section 34 s in this township, and are both fractional.

Some Townships are very complicated! Are there completions or extension surveys for which you need data????

Sec 2 Sec 1 Sec 11 Sec 12

Section Subdivisions Arrangement of lotting gives us the clues to how to subdivide a section Bona Fide Rights are tied to these records, so our surveys must do so as well Remember that junior/senior issues, including odd parentheticals, double corners, and heavy bearings, can all impact locations of parcels

Completions with jr/sr inside the section

Parallel lines on partially surveyed sections Suppose the NE1/4 of Section 15 went to patent, and assume the GLO never did a completion survey here. How would you set the C1/4? Parallel lines to intersect = C1/4

Completions with jr/sr inside the section Lotting present No lotting present

What did we learn? Research the record Be sure you have all of it Let the plat tell you what to do Recognize that fractional sections exist, and can come in some very surprising places NEVER assume anything when working in the PLSS

Course Objectives Met? Understand the definition of a fractional section from the surveyor s viewpoint See the Federal Law on this topic, and learn how and when to apply it Learn how to compute a weighted mean bearing See how this applies to completions surveys

Subdivision of Fractional Sections ISPLS 2017