3-74. Revised Statutes, secs. 2396, 2397 (43 U.S.C. 752. 752 and 753), contain the fundamental provisions for the subdivision of sections into quarter sections and quarter-quarter sections. The sections are not subdivided in the field by Bureau of Land Management cadastral surveyors unless provision is made in the special instructions, but certain subdivision-of-section lines are always protracted upon the official plat.

  3-75. Under the rectangular system the unit of survey is the township of 36 sections. The unit of subdivision is the section of 640 acres. Under the general land laws, broadly, the unit of administration is the quarter-quarter section of 40 acres. The function of the cadastral surveyor of the Bureau of Land Management has been fulfilled when he has executed and monumented his survey properly and returned an official record in the form of detailed field notes and a plat. The plats are constructed in harmony with the field notes returned by the surveyor. The lands are identified on the ground by fixed monuments established in the survey. A United States patent conveys the title to an area defined by those fixed monuments and related by description and outline to the official plat.

  3-76. The local surveyor is employed as an expert to identify lands which have passed into private ownership. This may be a simple or a most complex problem, depending largely upon the condition of the original monuments as affected principally by the lapse of time since the execution of the original survey. The work usually includes the subdivision of the section into the fractional parts shown upon the approved plat. In this capacity the local surveyor is performing a function contemplated by law. He cannot properly serve his client or the public unless he is familiar with the legal requirements concerning the subdivision of sections. In the event that the original monuments have become lost, the surveyor needs to be familiar with the scheme of the original survey, the record of the particular survey involved, and the principles upon which the courts have based rulings with regard to corner restoration.

The Bureau of Land Management assumes no control or direction over the acts of local and county surveyors in the matters of subdivision of sections and reestablishment of lost corners of original surveys where the lands have passed into private ownership, nor will it issue instructions in such cases. It follows the general rule that disputes arising from uncertain or erroneous location of corners originally established by the United States are to be settled by the proper local authorities or by amicable adjustment. The Bureau desires that the rules controlling the acts of its own cadastral surveying service be considered by all other surveyors as merely advisory and explanatory of the principles which should prevail in performing such duties.

Subdivision by Protraction

  3-77. Upon the plat of all regular sections the boundaries of the quarter sections are shown by broken straight lines connecting the opposite quarter-section corners. The sections bordering the north or west boundary of a normal township, excepting section 6, are further subdivided by protraction into parts containing two regular half-quarter sections and four lots. Section 6 has lots protracted against both the north and west boundaries, and so contains two regular half-quarter sections, one quarter-quarter section, and seven lots. The position of the protracted lines and the regular order of lot numbering are shown in figure 46. The lots are numbered in a regular series progressively from east to west or from north to south in each section. The lots in section 6 are numbered commencing with No. 1 in the northeast, thence progressively to No. 4 in the northwest, and south to No. 7 in the southwest fractional quarter-quarter section.

  3-78. The regular quarter-quarter sections are aliquot parts of quarter sections based upon midpoint protraction. These lines are not indicated upon the official plat.

  3-79. Sections which 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 to form a suitable basis for the administration of the public lands remaining undisposed of, and to describe the latter separately from the segregated areas.

  3-80. The meander line of a body of water and the boundary lines of private claims are platted in accordance with the lines run or connections made in the field. The sections invaded are subdivided as nearly as possible in conformity with the uniform plan. The subdivision-of-section lines are terminated at the meander line or claim boundary, but the position of the subdivision-of-section lines is controlled precisely as though the section had been completed regularly. In the case of a section whose boundary lines are in part within the limits of a meanderable body of water, or within the boundaries of a private claim, the fractional section lines are completed in theory, and the protracted position of the subdivision-of-section lines is controlled by the theoretical points so determined.

  3-81. Fractional sections are subdivided so as to contain as many aliquot parts as possible, but a departure from this practice is made where it would result in poorly shaped fractional lots. In the case of fractional lots along the north and west boundaries of a township, and in other similar cases where a lot has a full normal width of 20 chains in one direction, it is generally advisable to avoid areas of less than 10 or more than 50 acres. In the instance of fractional lines along a meander line or other irregular broken boundary, where the width of the lot in both directions may be considerably less than 20 chains, resulting in tracts of more compact form, it is generally better to avoid an area of less than five or more than 45 acres. Extreme lengths or narrow widths should be avoided. The longer direction should extend back from a meander line or claim boundary rather than along it. It is inconsistent that a fractional lot lie partly in two sections, and it is generally better, when consistent with other rules, to avoid fractional lots extending from one into another fractional quarter section.

  3-82. To visualize a uniform system for numbering lots of fractional sections, imagine the section divided by parallel latitudinal lines into tiers, numbered from north to south. Then, beginning with the eastern lot of the north tier, call it No. 1, and continue the numbering west through the tier, then east in the second, west in the third, east in the fourth tier, until all fractional lots have been numbered. These directions are maintained even though some of the tiers contain no fractional lots. A lot extending north and south through two, or part of two tiers, is numbered in the tier containing its greater area. This method of numbering applies to any part of a section. A section that has been partly surveyed at different times should have no duplication of lot numbers.

Figure 46. -  Examples of subdivision by protraction.  Click to enlarge.

Figure 47. - Examples of subdivision of fractional sections. Click to enlarge.

  3-83. When the length or width of a township exceeds 480 chains to such an extent as to require two or more tiers of lots adjoining the north or west boundary, the usual past practice has been to lot all of the area beyond the regular legal subdivisions as shown in figure 48(a) and 49(a). Henceforth, in order to avoid possible confusion of descriptions, the lotting should be extended throughout the fractional half of the section as shown in figures 48(b) and 49(b). This will also apply to the platting of resurveyed sections insofar as public land is involved. In modern practice, sections in excess of 120 chains are avoided by the creation of half-township or half-range numbers. This cannot be done where the elongated sections are situated in the interior of a township as the result of partially completed but grossly irregular former subdivisions. Lotting will then be extended as necessary.

  3-84. It if has been necessary to establish a sectional guide meridian or a sectional correction line, fractional lots may result along the east or south boundary of the township. The sections bordering the defective boundaries are subdivided on the same plan as sections bordering the north and west boundaries of a normal township.

Subdivision by Survey

  3-85. The rules for subdivision of sections by survey are based on the laws governing the survey of the public lands. Some cases arise, however, which are not covered by these rules and require the advice of the Bureau of Land Management. The letter of inquiry should contain a description of the particular tract or corner, with reference to township, range, and section of the public surveys, together with a diagram showing conditions found.

Figure 48(a). - Elongated section-subdivision by protraction.   Click to enlarge.

Figure 48(b). - Extension of lotting in elongated section. Click to enlarge.

Figure 49(a). -  Elongated section-subdivision by protraction.  Click to enlarge.

Figure 49(b). - Extension of lotting in elongated section.  Click to enlarge.

Order of Procedure in Survey

  3-86. Since the corners established in the original survey are controlling, it is essential that these corners be found, or properly restored, before the actual field work involving the subdivision of section is undertaken. The section boundaries should be retraced to develop the actual bearings and lengths of the lines between the corners.

The order of procedure is: First, identify or reestablish the corners on the section boundaries, including determination of the points for the necessary one-sixteenth section corners. Next, fix the boundaries of the quarter sections; and then form the quarter-quarter sections or small tracts by equitable and proportionate division. The following methods should be employed:

Subdivision of Sections Into Quarter Sections

  3-87. To subdivide a section into quarter sections, run straight lines from the established quarter-section corners to the opposite quarter-section corners. The point of intersection of the lines thus run will be the corner common to the several quarter sections, or the legal center of the section.

Upon the lines closing on the north and west boundaries of a regular township the quarter-section corners were established originally at 40 chains to the north or west of the last interior section corners. The excess or deficiency in measurement was thrown into the half mile next to township or range line, as the case may be. If such quarter-section corners are lost they should be reestablished by proportionate measurement based upon the original record.

Where there are double sets of section corners on township and range lines, the quarter-section corners for the sections south of the township line and east of the range line usually were not established in the original surveys. In subdividing such sections new quarter-section corners are required, so placed as to suit the calculations of the areas that adjoin the township boundary, as indicated upon the official plat, adopting proportional measurements where the new measurements of the north or west boundaries of the section differ from the record distances.

Subdivisions of Fractional Sections

  3-88. The law provides that where opposite corresponding quarter-section corners have not been or cannot be fixed, the subdivision-of-section lines shall be ascertained by running from the established corners north, south, east, or west, as the case may be, to the water course, reservation line, or other boundary of such fractional section, as represented upon the official plat.

In this the law presumes that the section lines are due north and south, or east and west lines, but usually this is not the case. Hence, in order to carry out the spirit of the law, it will be necessary in running the center lines through fractional sections to adopt mean courses where the section lines are not on due cardinal, or to run parallel to the east, south, west, or north boundary of the section, as conditions may require, where there is no opposite section line.

Subdivision of Quarter Sections

  3-89. Preliminary to the subdivision of quarter sections, the quarter-quarter- or sixteenth-section corners will be established at points midway between the section and quarter-section corners, and between the quarter-section corners and the center of the section, except on the last half mile of the lines closing on township boundaries, where they should be placed at 20 chains, proportionate measurement counting from the regular quarter-section corner.

The quarter-quarter- or sixteenth-section corners having been established as directed above, the center lines of the quarter section will be run straight between opposite corresponding quarter-quarter- or sixteenth-section corners on the quarter-section boundaries. The intersection of the lines thus run will determine the legal center of a quarter section.

Subdivision of Fractional Quarter Sections

  3-90. The subdivisional lines of fractional quarter sections will be run from properly established quarter-quarter- or sixteenth-section corners, with courses governed by the conditions represented upon the official plat, to the lake, water-course, reservation, or other irregular boundary which renders such sections fractional.

  3-91. Reasonable discrepancies between former and new measurements may generally be expected when retracing the section boundaries. The shortage or surplus in distributed by proportion in establishing a sixteenth-section corner. For example: The length of the line from the quarter-section corner on the west boundary of section 2 to the north line of the township, by the official survey was reported as 43.40 chains, and by the county surveyor's measurement was found to be 42.90 chains. The distance which the sixteenth-section corner should be located north of the quarter-section corner would be determined by proportion as follows: As 43.40 chains, the official measurement of the whole distance, is to 42.90 chains, the county surveyor's measurement of the same distance, so is 20 chains, original measurement, to 19.77 chains by the county surveyor's measurement. By proportionate measurement in this case the sixteenth-section corner should be set at 19.77 chains north of the quarter-section corner, instead of 20 chains north of said corner, as presented on the official plat. In this manner the discrepancies between original and new measurements are equitably distributed.

Figure 50. -  Examples of subdivision by survey showing relation of official measurements and calculated distances to remeasurements, and indicating proportional distribution of differences.  Click to enlarge.


  3-92. By way of recapitulation it is emphasized that when entrymen have acquired title to certain legal subdivisions they have become the owners of the identical ground area represented by the same subdivisions upon the official plat. It is a matter of expert or technical procedure to mark out the legal subdivisions called for in a patent, and entrymen are advised that a competent surveyor should be employed. The surveyor must identify the section boundaries and locate the legal center of the section in order to determine the boundaries of a quarter section. Then, if the boundaries of quarter-quarter sections, or fractional lots, are to be determined on the ground, the boundaries of the quarter section must be measured, and the sixteenth-section corners fixed in accordance with the proportional distances represented upon the approved plat. Finally, the legal center of the quarter section may be duly located. Thus will be produced in the field the figure represented upon the plat, every part of the former in true proportion to the latter, where the elements of absolute distance and area have given way to corresponding proportional units as defined by fixed monuments established in the original survey.