Cadastral Surveying and the Public Land Survey System
Cadastral Surveying and the Public Land Survey System
This domain tests the PLSS as it actually exists in Colorado: the 6th Principal Meridian framework, section subdivision, government lots, and the restoration rules of the BLM Manual of Surveying Instructions (2009).
Colorado framework
- Colorado lies entirely within the 6th Principal Meridian system. The baseline is the 40th parallel - Baseline Road in Boulder - with townships numbered north and south of it and ranges numbered west of the meridian.
- Townships are nominally 6 miles square and divided into 36 sections of 640 acres, numbered from the northeast corner: 1 through 6 eastward across the top tier, 7 through 12 back westward, serpentine to 36 in the southeast corner.
- Sections 16 and 36 are school sections. In Colorado these are state trust lands administered by the State Land Board, which constrains access and use.
- Fractional sections along the north and west tiers create government lots. The acreage shown on the official plat governs the lot; never assume a lot is exactly 40 acres.
Subdivision rules
- Quarter corners are restored by single proportionate measurement between the controlling section corners.
- The section is divided by straight lines between opposite quarter corners, then halved to 40s; the 2009 Manual fixes the order of subdivision and the treatment of excess and deficiency.
- Closing corners are restored by double proportionate measurement, with the position on the line being closed onto controlling.
- Meander lines along rivers approximate the water boundary; they do not fix title.
Worked example
The north line of Section 14, between the section corners common with Section 11, measures 5,286.20 ft. The quarter corner on that line is lost.
Single proportion: 5,286.20 ÷ 2 = 2,643.10 ft from each controlling corner.
Now read the description NW1/4 of the NE1/4 of that section. Halving the section gives the NE1/4 (160 acres); halving again gives the NE1/4 of the NE1/4, and the northwest 40 of it is the NW1/4 NE1/4 - 40 acres, subject to any excess or deficiency apportioned under the Manual rules.
Traps
- Re-setting quarter corners at record distances on a line that measures long or short.
- Assigning exactly 40 acres to a government lot.
- Assuming every section contains 640 acres; excess and deficiency must be apportioned, not ignored.
- Confusing closing corners (double proportion) with interior section corners.