Cadastral Survey
An official survey that creates, marks, defines, retraces, or reestablishes the boundaries and subdivisions of the public lands, made under the direction of the Bureau of Land Management.
Detailed Definition
A cadastral survey is a survey that creates, marks, and defines land boundaries. In the federal system it is the official survey of the public lands, made under the direction of the Bureau of Land Management (BLM).
BLM's Glossary of Surveying and Mapping Terms defines it as "a survey which creates, marks, defines, retraces or reestablishes the boundaries and subdivisions of the public land of the United States." BLM's Manual of Surveying Instructions (2009) puts it similarly: "A cadastral survey creates or reestablishes, marks, and defines boundaries of tracts of land" (section 1-4).
What an official survey includes
Under the Manual's general plan, each cadastral survey includes (section 1-4):
- a request for survey
- special instructions and assignment instructions
- a field note record of the observations, measurements, and monuments
- a plat representing the official survey
All are subject to review, approval, or acceptance by the Director of BLM, and "a cadastral survey is not complete until it is officially filed with the BLM." The glossary adds that public lands are deemed surveyed only when the survey has been accepted and its plat filed, and "no subdivisions of the public lands may be conveyed or in any way disposed of until so identified."
Its legal standing
The Manual calls the official survey "the highest form of boundary evidence available to the Federal Government" and "a formal decision by the Federal Government" that "is subject to administrative or judicial appeal" (section 1-5). It distinguishes a local survey, which "is an opinion on the location of a boundary based on a survey that does not contain every element of an official survey," and an administrative survey, which is a local survey made for a federal agency.
Kinds of cadastral surveys
The Manual's chapters cover several kinds:
- Original surveys that extend the rectangular system over unsurveyed land
- Resurveys, both dependent and independent, that retrace and restore earlier surveys
- Special surveys of nonrectangular parcels
- Mineral surveys of mining claims
The glossary defines a mineral survey as a cadastral survey of a lode or placer mining claim or millsite, executed by a U.S. Mineral Surveyor "for the purpose of marking the legal boundaries of mining claims on the public domain." The Manual explains that the mineral survey is part of the patent application process, and that "since 1994, Congress has prohibited the filing of new mineral patent applications" (section 10-106).
Why it matters in research
The official plats and field notes of cadastral surveys are the record that PLSS land descriptions refer to. For mining claim research they show which land is surveyed, where section and quarter corners were set, and where approved mineral surveys segregate patented ground from the surrounding sections. A local survey, a GIS layer, or a map is, at most, evidence. The filed official survey is the record it must be checked against.
Related Terms
PLSS
The Public Land Survey System, the rectangular survey system that divides the public lands into townships, ranges, and sections and serves as the basis for describing them.
BLM (Bureau of Land Management)
The Bureau of Land Management, the Interior Department agency that manages the federal mineral estate and records and maintains unpatented mining claims and sites.
Section Corner
A surveyed corner at the end of a section boundary in the Public Land Survey System, monumented on the ground and controlling the boundaries of the sections it marks.
Monument
A physical object, such as an iron post, marked stone, or tree, that marks the location of a surveyed corner on the ground and serves as the primary evidence of its position.
Bearing Tree
A tree near a survey corner, marked with prescribed scribe marks, whose species, size, direction, and distance from the corner are recorded so the corner can be relocated.
Mineral Survey
An official cadastral survey of a lode claim, placer claim, or mill site, made by a U.S. mineral surveyor under BLM authority, usually as part of a mineral patent application.
Protraction Diagram
An official BLM diagram that lays the PLSS grid over unsurveyed land so it can be described by township, range, and section. It is not a survey and sets no monuments.
Magnetic Declination
The angle, on a given date, between magnetic north as shown by a compass needle and true north. PLSS and mineral surveys report bearings from the true meridian, not magnetic north.