SUBDIVISION OF SECTIONS INTRODUCTION The U.S. land surveyor's work is usually completed with the physical placement of the specified monuments at section and quarter section corners and the filing of notes with the Bureau of Land Management. Subsequent work involved in placing quarter-quarter, or sixteenth, corner points is the task of private surveyors. A private surveyor who engages in subdivision of sections should be thoroughly familiar with the principles and practices of the original survey work that was done by U.S. land surveyors in that area. NUMBERING OF SECTIONS The sections are numbered beginning with 1 in the northeast section of the township and progressing west and east alternately along the tiers of sections until all have been numbered. Figure 1 shows the numbering of one township into sections.

Figure 1 Numbering of Sections

SUBDIVIDING OF SECTIONS

Sections are usually subdivided into quarter sections, except for those sections on the westerly range and on the northerly tier of the township. These sections will, in general, contain either more or less than 640 acres because of accumulated survey errors in the northerly 20 chains of each range or meridional section line or because of the convergence of the meridians. Such sections (Figure 2) are commonly subdivided into quarter sections, half-sections, quarter-quarter-sections, and numbered lots.

Figure 2 Subdivision of Section

Similarly special subdivisions are required in the southern tier or in the eastern range of sections when the south or the east boundary of the township is defective in alignment as shown in Figure 3.

Figure 3 Defective Townships

Fractional subdivisions are also required when there is a lake or other navigable body of water within the section or when there are patented mineral claims, private land claims, reservations, state lines, and other special surveys in the area. The cadastral engineers of the Bureau of Land

Management protract these subdivisions of section lines on the official plat of the township. Local surveyors customarily execute these surveys. Before a section is subdivided, it is necessary to identify the section and quarter section corners or to relocate them. SUBDIVIDING INTO QUARTER-SECTIONS When the quarter-section corners have been identified, two straight lines are run between opposite quarter-section corners to divide the section into four quarters. The intersection of these lines is monumented and is the legal center of the section. When opposite quarter-section corners have not or cannot be fixed, as when one falls in a lake or river or falls outside of the public domain, subdivision-of-section lines are run from those quarter-section corners located, by using the bearing of one line or the mean bearing of two lines. SUBDIVIDING OF QUARTER-SECTIONS In subdividing quarter sections, the quarter-quarter- or sixteenth-section corners are established at points midway between the section and quarter section corners, and between the quarter-section corners and the center of the section. An exception to this is made on the last half-mile of those lines closing on township boundaries. Here the corners are set at 20 chains, proportionate measurement, from the preceding quarter-section corner so that survey discrepancies are placed in the last distance. When the sixteenth-section corners have been established, straight lines are run between opposite corners to divide the quarter section into sixteenths of a section. In a manner similar to that outlined above, sections can be subdivided into parts which are, respectively, 1/64, 1/256, and 1/1024. FRACTIONAL LOTS The provisions of section division described above apply to sections of normal size and to fractional parts thereof. These sections bordering on the north and west boundaries of a township, excepting section 6, are subdivided by protractions on the official plat into parts representing two half-quarter sections and four lots (Figure 2). The lots are numbered from 1 to 4 in an east-to west direction or in a north-to-south direction except in section 6, which lies in the northwest corner of the township. In section 6, there are 7 lots as indicated in Figure 2. Similar lots may be formed on the south and east sides of a township when these boundaries are defective as shown in Figure 3. The subdivision of regular sections is simple. Sixteenth corners are placed halfway between section and quarter section corners as shown in Figure 4.

Figure 4 Regular Section

Straight lines connecting sixteenth corners complete the job. Note that the distance measured from the northeast section corner to the north quarter-corner is 40.10 chains. Regardless of the distance recorded by the original surveyor, the sixteenth corner is placed midway between the two original monuments in a regular section.

Figure 5 Fractional Section

Subdivision of an irregular section is not that simple. Figure 5 depicts section 3 in a township.

The original distances measured by U.S. land surveyors are shown in parentheses and confirm that in U.S. surveys whatever error develops is placed in the last half-mile or last quarter mile. Measured distances are shown in square brackets In the original survey, the distance between the east quarter corner and the northeast section corner was considered to be divided thus: from quarter-corner to sixteenth (unmarked) corner, 20.00 chains; and from sixteenth corner to northeast section corner, 20.50 chains. Any corrections must be made in the same proportion of measured distance to re-measured distance:

(40.50/40.80) = (20.00/X) X = 20.14 chains

(40.50/40.80) = (20.50/Y)

Y = 20.66 chains

This principle of proportioning the differences in fractional sections must be observed in subdivision surveys.

PROCEDURE FOR ESTABLISHING SECTION LINES Figure 6 shows the normal order of running lines in subdividing a township.

Figure 6 Order of Running Lines

Starting at the southwest corner of section 36, line 1 is run northerly. Quarter section and section corners are set along this line at distances of 40 and 80 chains, respectively. From the section corner just established, a random line, 2, is run easterly parallel to the south boundary of the township, a temporary quarter-section corner being set on this line. The "falling" of this line is determined. This falling is the distance from the point where the random line intersects the guide meridian to the standard corner previously set on the guide meridian. If the "falling" of the line is within allowable limits, the direction of the return course, which will join the section corners, is computed. This return line is then run, a permanent quarter-section corner being set midway along it. This process continued for section 25 by running line 3 northerly and parallel to the east township boundary and then running random line 4 easterly and closing back. Successive sections in the range are monumented until section 1 is reached. As indicated by the numbered lines in Figure 6, the process is repeated for each range in the township, the layout of the sections in the second range starting with line 12. On the last range, the random line 46 is run to the east and random line 47 is run to the west. TOWNSITES Town sites in the public domain are those areas within one or more townships, which are divided into streets, alleys, and blocks of lots. Many town sites, particularly those developed on the relatively flat prairies and plains, follow along rectangular lines closely correlated with the regular lines of the survey system. Other irregular town sites came into being, prior to subdivision surveys in the area, around trading posts and military establishments. The town site boundaries are surveyed, closed, and tied in with the public land system. All street, block, and lot lines are likewise staked out and a plat of the area prepared, showing the relationship of public survey lines to all lines in the town site. LOCATION OF ISLANDS The beds of navigable bodies of water below the high-water line do not form a part of the public domain. The sovereignty to such lands lies in the individual states in which the waterways are located. However, in the case of islands that were above high water prior to the date of admission into the Union, title was vested in the United States. Such islands are part of the public domain and are subject to survey. The islands are therefore to be located by triangulation, direct measurement, or other suitable method. A meander traverse, and the islands shown on the official plat or plats locate their shorelines. Township or section lines, which traverse the island, are located and regular township, section, and meander corners are set. MEANDER LINES Meander lines make some sections irregular. Figure 7 illustrates section 9, ordinarily a regular section that is partially covered by a lake.

Figure 7 Meander Lines

The dashed lines show what ordinarily would have been the division of the section into sixteenths, each approximately 40 acres in area. Each parcel cut by the lake is numbered as a lot; the numbering begins in the upper right-hand corner and is carried westward in the northern tier, and back to the east in the next tier, without skipping a number. The regular parcels are designated by location, such as the southeast quarter of the southwest quarter.