Mining & GIS Glossary

The annual labor or improvements, worth at least $100 per mining claim, that a claimant under the small miner waiver performs instead of paying the BLM maintenance fee.

A test that measures the amount of one or more specific metals or minerals in a sample of ore or rock, such as a fire assay for gold.

A legal subdivision of a PLSS section made by dividing it into halves or quarters, such as the NE1/4 or the SW1/4NE1/4. Lots are the other kind of legal subdivision.

A machine-based system that, for objectives people set, makes predictions, recommendations, or decisions. Federal law defines the term at 15 U.S.C. 9401(3).

The top or outcrop of a vein, lode, or ledge. Under 30 U.S.C. 26, the lode claim that contains the apex may follow the vein downward beyond its vertical side lines.

A sworn challenge by a rival mining claimant to a mineral patent application, filed during the 60-day publication period and followed by a court suit to decide the right of possession.

The end of a mining claim, either by the owner voluntarily giving it up with intent to abandon, or by statute when a required recording or filing is missed.

A recorded change to a mining claim's notice or certificate of location that corrects defects, fixes the description, repositions lode side lines, or reduces its size, relating back to the original location date.

Having software or machines carry out tasks people would otherwise do by hand. It ranges from fixed rules to systems that learn from examples.

Application Programming Interface: a defined access point that lets one program request data or functions from another. Many government data services publish APIs.

The boundary drawn around the ground being researched, such as a list of townships and sections or a mapped polygon, that sets which records are pulled.

The yearly payment or documents required to hold an unpatented mining claim: the maintenance fee or a waiver by September 1, and in some cases an annual FLPMA document by December 30.

A mining claim that BLM's Mineral & Land Records System (MLRS) shows with the case disposition Active, defined as adjudicated and accepted.

A condensed history of the title to land, summarizing every conveyance affecting it together with the liens, charges, and liabilities to which it may be subject.

The Bureau of Land Management, the Interior Department agency that manages the federal mineral estate and records and maintains unpatented mining claims and sites.

The preparation of ore to control its size, remove unwanted material, or raise its grade, by steps such as crushing, grinding, flotation, gravity or magnetic concentration, and leaching.

The east-west survey line through an initial point, run on a true parallel of latitude, from which townships in the Public Land Survey System are numbered north and south.

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.

One of 12 Bureau of Land Management offices, each with jurisdiction over one or more states, where mining claims are recorded and fees and annual documents are filed.

The case number BLM assigns to a mining claim or site when it is recorded with full fees. MLRS numbers pair a state code with nine digits; older LR2000 numbers remain searchable.

A GIS operation that draws polygons a set distance around points, lines, or polygons, used to find what lies within that distance.

The series of conveyances affecting a tract, arranged in order from the government or other original source of title down to the present holder.

Mining-related activity on public lands that ordinarily causes no or negligible disturbance, for which no notice to BLM is required under 43 CFR subpart 3809.

A cylinder of rock cut by a hollow drill bit and brought to the surface, or a split part of that core taken for assay, showing the rock as it lies underground.

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.

The field of AI that interprets images and video, inferring properties of the world from imaging data. USGS has tested it for extracting features from historical maps.

The document recorded in the county and filed with BLM to establish a mining claim. Some states call it a certificate and require it in addition to the notice posted on the ground.

A post, stone, or other marker a locator sets at a corner of a mining claim to mark its boundary on the ground. Federal law requires the marking; state law sets the monuments.

A group of contiguous mining claims held by the same owner or group of owners, usually laid out to cover one mineral deposit and the ground needed to work it.

The ground a mining claim holder can actually hold once overlaps with other mining claims, closed land, and defects in the record are taken into account, as opposed to the acreage filed.

The work of correcting defects and gaps in title identified in a title opinion or title report, by obtaining and recording documents, filings, or court orders.

The number BLM's Mineral & Land Records System (MLRS) assigns to each kind of case, such as a lode claim, placer claim, mill site, tunnel site, notice, or plan of operations.

The number of mining claims in a unit of area, such as a section or township, used to see where ground is being held and how that changes over time.

Finding and reading the records of the mining claims on a tract, from BLM and the county, to learn what is claimed, by whom, and whether the filings were made on time.

Tracking BLM mining claim records over time to see who holds ground in an area, how their positions change, and what those changes suggest.

An overlap or competing interest between a mining claim and another mining claim or site, a patent, a lease, or a withdrawal on the same ground.

Recording a mining claim's location notice or certificate, and later documents, in the local recording office of the county or borough where the mining claim lies, as state law requires.

A mining claim whose case BLM's Mineral & Land Records System (MLRS) shows as Closed: abandoned, relinquished, forfeited, voided, or otherwise ended.

The owner of all or part of an unpatented mining claim or site under federal law, who may be someone other than the original locator.

The older name for a standard parallel: an east-west PLSS line, normally every 24 miles from the base line, on which township measurements restart to correct for convergence.

An outstanding claim or encumbrance which, if valid, would affect or impair the title of the owner of a particular estate.

The rules that turn a position into numbers: latitude and longitude on a datum, or eastings and northings on a projected grid such as UTM or State Plane.

A working interest whose share of drilling or operating costs is paid by another party, which recovers that money out of production before the carried party shares in it.

A lease provision that keeps a lease in force after the primary term, or after production stops, while drilling or reworking operations continue without gaps longer than the lease allows.

The finding of a valuable mineral deposit within the boundaries of a mining claim. A lode or placer claim is not valid until a discovery is made.

Machine learning built on neural networks with many hidden layers. GAO reports it became prevalent in the 2010s and advanced computer vision and language processing.

The monument a locator sets at the point of discovery on a mining claim, usually carrying the posted location notice. Some states put the notice at a corner or on a location monument instead.

An instrument signed by an owner that states the owner's interest in production from a property and directs the payor to distribute the proceeds accordingly.

A chain of automated steps that collects data from sources, prepares it, and delivers it for analysis or use, ideally with a record of where each item came from.

The status BLM's Mineral & Land Records System (MLRS) gives a case, such as Active, Closed, Filed, Under Review, or On Appeal.

A digital elevation model: a raster grid of bare-earth ground elevations, with trees, buildings, and other surface objects removed.

The reference frame that coordinates or heights are measured from. The same point has different coordinates on different datums, such as NAD 27 and NAD 83.

The division of mineral or leasehold rights under a tract by depth or formation, so that different parties hold rights above and below a stated depth or in different zones.

The right of a lode claim owner to follow a vein downward beyond the vertical side lines of the claim, when the apex lies inside the claim, limited by vertical planes through the end lines.

Extract, Transform, Load: pulling data from a source, cleaning and reshaping it, and writing it into a target database. It is the core of most data pipelines.

A right to or interest in land held by someone other than the owner that makes the land subject to a charge or liability, such as a mortgage, lien, lease, or tax.

An interest or right in land owned by another that entitles its holder to a specific limited use, such as crossing the land, laying a pipe, or running a power line.

Work that tests ground for a mineral deposit, such as sampling, trenching, and drilling. BLM defines it as disturbance greater than casual use to evaluate mineral values.

Ownership of a share of an interest in land or minerals rather than the whole of it, such as an undivided one-half of the minerals or a one-quarter interest in a mining claim.

The Federal Land Policy and Management Act of 1976, the statute under which BLM manages the public lands. It requires mining claims to be filed with BLM and governs withdrawals.

In mining, a comprehensive technical and economic study of the selected development option for a mineral project, rigorous enough to support an investment decision or project financing.

The loss of an unpatented mining claim or site by operation of law for failing to record, pay the location or maintenance fee, file a waiver or annual document, or for locating on closed land.

Lands owned by the United States. For mining claims, BLM's rules define federal lands as land owned by the United States and subject to location under the General Mining Law.

In Esri's geodatabase model, a collection of features that share one geometry type (point, line, or polygon) and one set of attribute fields.

An agreement by which a lease owner (the farmor) agrees to assign all or part of its interest to another party (the farmee), which earns the assignment by drilling or meeting other conditions.

A state regulatory action that compels mineral owners within a spacing unit to participate in drilling operations when voluntary agreement cannot be reached.

The concentration of a metal or mineral in rock, such as ounces of gold per ton or percent copper, which together with tonnage decides whether a deposit can be mined at a profit.

Artificial intelligence applied to maps, imagery, and location data. USGS uses machine learning to georeference historical maps and model mineral prospectivity.

A geographic information system: software and data that store, analyze, and display information tied to locations on the earth.

Using location to answer questions across data layers: what overlaps, what is near, what lies where, and what follows the terrain.

Turning a written location, such as a street address or a legal land description, into map coordinates or a polygon.

Esri's native format for GIS data: feature classes, tables, rasters, and the rules between them, held in a folder, a single file, or a relational database.

An IETF standard (RFC 7946) for encoding geographic features in JSON, with coordinates in WGS 84 longitude and latitude, in that order.

Describes a lease that continues past its primary term because oil or gas is being produced in paying quantities from the lease or from lands pooled or unitized with it.

The point where a principal meridian and its base line cross, serving as the origin for Public Land Survey System townships and ranges in a region.

The later of two mining claims covering the same ground. It gains the overlap only if the earlier mining claim was not valid or had ended when the later one was located.

A mining claim for minerals that occur in veins, lodes, ledges, or other rock in place, limited to 1,500 feet along the vein by 600 feet wide.

Minerals on federal land that are acquired by locating a mining claim under the Mining Law, as opposed to leasable minerals and salable mineral materials.

The notice a locator posts on a mining claim and records with the county and BLM, giving the locators, the date of location, and a description of the ground claimed.

The written statement in a deed, patent, lease, or order that identifies the land it covers, precisely enough that a surveyor can locate it on the ground.

A generative AI model trained on large amounts of text that produces language by predicting the next word. NIST warns it can state false content with confidence.

The sum paid by a lessee to the lessor as consideration for granting a lease, as distinct from the rentals and royalties paid over the life of the lease.

The legal condition of a tract of federal land: ownership of surface and minerals, withdrawals, segregations, reservations, and the rights already attached to it.

The person who locates a mining claim or site by staking it, posting the notice, and recording it, and who is named in the location notice. Ownership may later pass to others.

In the PLSS, a numbered legal subdivision of a section that is not an aliquot part, created where a section cannot be divided evenly, such as along township edges or water.

A description that identifies land by its place in the Public Land Survey System: principal meridian, state, township, range, section, and lots or aliquot parts.

A parcel of federal land on which a claimant asserts the right to possess and develop a valuable mineral deposit under the Mining Law of 1872.

Ownership of the minerals in a tract of land, which may be held together with the surface or severed from it and owned by someone else, including the United States.

The process of locating a mining claim on the ground under state law and recording it with the county and BLM within 90 days of the date of location.

A location of up to 5 acres of nonmineral federal land, not contiguous to a vein or lode, used for activities that support a mining claim or for custom milling.

The ownership of the minerals beneath a tract of land, which can be held separately from the surface and, on federal land, is obtained by claim, lease, or sale depending on the mineral.

The act of May 10, 1872, that opens valuable mineral deposits on federal land to exploration and location, and still governs mining claims for locatable minerals.

The annual fee paid to BLM to hold an unpatented mining claim or site: $200 per lode claim, mill site, or tunnel site, and $200 per 20 acres of placer claim, due by September 1.

A concentration of material of economic interest in such form, grade, and quantity that there are reasonable prospects for economic extraction, classed as inferred, indicated, or measured.

The economically mineable part of a measured or indicated mineral resource, including diluting materials and allowances for losses, classed as probable or proven.

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.

A method of describing land by its boundary: from a point of beginning, along each course by bearing and distance, with calls to monuments and adjoiners, back to the start.

Computer systems that adapt and learn from data instead of following rules written out in advance. It is the branch of artificial intelligence behind most current AI tools.

The appropriation of federal land under the mining laws, by locating mining claims on land open to mineral entry and, historically, by entry for a mineral patent.

A contract by which the owner of minerals grants another the right to explore for and produce them for a stated term, in exchange for payments such as bonus, rental, and royalty.

A natural concentration of a useful mineral or metal in or on the earth, large and rich enough to be worth developing, or potentially so.

The Mineral Resources Data System, a USGS database of reports on mines, prospects, and mineral occurrences, most complete for the United States, no longer systematically updated.

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.

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.

Rights which attach only to mineral deposits, such as the right to explore for, develop, and extract them, as distinct from rights in the surface.

The field of computing that turns human language into a form a computer can analyze. NIST notes that general NLP tools often misread specialized jargon.

Exploration on public lands causing surface disturbance of 5 acres or less, conducted under a notice filed with BLM at least 15 calendar days before work begins, with a financial guarantee.

The share of production, or its proceeds, that a working interest owner actually receives after royalty, overriding royalty, and other burdens on production are deducted.

Rock or mineral material containing a metal or mineral in enough quantity and grade that it can be mined and processed at a profit.

Federal land that is open to the location of mining claims and sites under the General Mining Law, because it has not been withdrawn or segregated from mineral entry.

A share of production carved out of the lessee's interest in a lease, in addition to the royalty reserved to the lessor, and free of the costs of production.

An automated process that converts the image of text into machine-readable text. The Library of Congress states that OCR of historical documents always contains errors.

Comparing the boundaries of mining claims with each other and with withdrawals and land status to find where they coincide, then checking the records to see which overlaps are real.

A mining claim for minerals that are not in their original place, such as gold-bearing sand and gravel, limited to 20 acres per locator and 160 acres for an association.

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.

A mining claim for which the United States issued a mineral patent, passing title from the federal government into private ownership.

A document by which the United States passes title to public land. A mineral patent turns a mining claim or mill site into private land; no new patent applications have been accepted since October 1, 1994.

The north-south survey line through an initial point, run on the true meridian, from which ranges in the Public Land Survey System are numbered east and west.

Field shorthand for posting the location notice on a mining claim, the step that pairs with staking its boundaries.

Actual possession. In mining law, the limited protection of a prospector who occupies open public land and diligently works toward a discovery, good against rival locators but not the United States.

The search for a mineral deposit, from looking for outcrops to sampling, which comes before a discovery and the location of a mining claim.

The fixed initial period of an oil and gas lease, during which the lease stays in force without production if its other terms are met.

Combining separately owned tracts or interests within a spacing or drilling unit so that a well can be drilled and production shared among them, by agreement or by state order.

The operating plan BLM must approve under 43 CFR 3809 before mining on public lands, before exploration beyond 5 acres, and before any work beyond casual use in certain special areas.

Lands the United States obtained by cession from the original states or by treaty or purchase. Only public domain minerals are locatable under the Mining Law; acquired minerals are not.

How likely an area is to contain a mineral deposit of a particular type, judged from its geology and the deposits already known nearby.

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.

A mathematical method for putting the curved surface of the earth onto a flat map or grid. Every projection distorts area, shape, distance, or direction.

A lease provision under which, after the primary term, the lease ends as to acreage that is not within a producing, pooled, or spacing unit, even though production elsewhere holds the rest.

A surveyed corner at the end of a quarter-section boundary on a section line, normally halfway between section corners, that controls the quarter-section lines inside the section.

A deed that conveys whatever interest the grantor has in the described land, without any promise that the grantor has any interest or that the title is free of encumbrances.

One of the four parts of a PLSS section, nominally 160 acres, named NE1/4, NW1/4, SW1/4, or SE1/4 and bounded by straight lines between opposite quarter corners.

A lawsuit in which a party claiming an interest in land brings in anyone asserting an adverse claim, so the court can decide the claims and bar the losers from asserting them again.

The work required to restore land disturbed by mining or exploration, such as regrading, revegetation, plugging drill holes, and removing structures, backed on BLM land by a financial guarantee.

Gathering information about the Earth from a distance by measuring reflected and emitted energy, usually from satellites or aircraft.

A share of production, or of its value, paid to a lessor or other royalty owner without bearing the costs of drilling and producing.

In the PLSS, a north-south column of townships, numbered east or west from the principal meridian. R. 20 E. is the twentieth column east of the meridian.

A landman's working list of the recorded instruments affecting a tract, prepared from courthouse and other title sources as the foundation for an abstract and a title opinion.

The legal right to cross the lands of another, or the strip of land used for a road, pipeline, or power line. On BLM land, a grant authorizing use of public land for a specified purpose.

GIS data stored as a grid of cells, each holding a value such as an elevation, a color, or a class. Used for imagery and continuous surfaces.

Land where the surface rights and the mineral rights are owned by different parties, most often a private surface over minerals reserved to the United States.

In surface mining, the amount of waste rock or overburden that must be removed to reach a unit of ore, such as 3 tons of waste for each ton of ore.

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.

To mark the boundaries of a mining claim on the ground with posts or monuments, as federal law and the law of the state where the mining claim lies require.

The ranking of rival interests in the same ground, the earlier ahead of the later. Federal law ties some mining claim rights to dates, but BLM leaves disputes over possession to the courts.

The earlier of two mining claims covering the same ground. Its priority holds only while the earlier location stays valid, recorded, and maintained.

A temporary removal of public land from some or all of the public land laws, including the mining laws, usually while a proposed withdrawal, sale, or exchange is under consideration.

A waiver of the annual BLM maintenance fee for a claimant who, with all related parties, holds 10 or fewer mining claims and sites and performs annual assessment work instead.

A payment that keeps an oil and gas lease in force while a well capable of producing is shut in, such as for lack of a market or production facilities.

Data that identifies where something is on the earth and what it is like, stored as vector features, raster grids, or coordinates in records.

Land granted by Congress to a state, usually at statehood, and held in trust to earn revenue for schools and other beneficiaries. It is state land, not federal land open to mining claims.

The set of maps, location notices, monument lists, and recording documents prepared before fieldwork so mining claims can be staked, posted, and recorded correctly and on time.

The unit of subdivision of a PLSS township, nominally one mile square and 640 acres. Each township has 36 sections, numbered from 1 in the northeast to 36 in the southeast.

All rights in the land excepting the oil, gas, and mineral rights to underground deposits. The surface may be owned separately from the minerals.

Land in which the mineral estate has been separated from the surface estate by a reservation, exception, or separate conveyance, so the two are held as distinct interests.

Esri's published vector data format: a main file of shapes (.shp), an index (.shx), and a dBASE attribute table (.dbf) that travel together.

A GIS operation that copies attributes from one layer to another based on where features sit relative to each other, not on a shared field.

The area of land assigned by a state conservation agency to a well in a pool, with its size, shape, and permitted well location set by order.

The three parts of a Public Land Survey System land description: a 6-mile-square township located by township and range numbers, divided into 36 sections of nominally 640 acres.

A subsurface right-of-way under federal land open to mineral entry, used to reach lode mining claims or to explore for blind veins, up to 3,000 feet long.

The finely ground material left over after the valuable metal or mineral has been extracted from ore, usually stored in an impoundment or pile.

A written legal opinion on the ownership of land or minerals, based on the record, that identifies the owners, the exceptions and defects found, and the steps needed to cure them.

A sale, assignment, inheritance, or other conveyance of all or part of the interest in an unpatented mining claim, effective under state law and filed with BLM and the county.

In the PLSS, the unit of survey: a nominal six-mile square of 36 sections, and also the row of such squares numbered north or south of the base line.

A map service that delivers pre-rendered map tiles at fixed scales, so a viewer loads only the tiles it needs. OGC standardizes it as WMTS and OGC API - Tiles.

A mining claim on federal land for which no patent has been issued. The claimant holds a possessory right to the minerals and the United States keeps title to the land.

Combining leases and tracts over all or part of a field or reservoir into one unit, developed and operated as a single property under an approved plan.

Rights established before land was withdrawn or segregated that the closure does not take away. For a mining claim, it means a location with a valuable mineral discovery made before the withdrawal date.

A mining claim or site with no legal effect, either from the start (void ab initio), by operation of law after a missed requirement, or by a BLM decision after a contest.

GIS data that stores features as points, lines, and polygons defined by coordinates, each linked to a row of attributes.

Building the steps of a business process into software so each item moves from start to finish the same way, with records captured along the route.

An action by Congress, the President, the Secretary, or another agency that withholds federal land from location or entry under some or all of the public land laws, including the mining laws.

A monument set near a mining claim corner that cannot be marked in its true position because the ground is impracticable or dangerous, marked to show where the true corner lies. Allowed in some states and not others.

The interest in an oil and gas lease that carries the right to explore, drill, and produce, together with the obligation to pay the costs of those operations.

An Open Geospatial Consortium (OGC) standard for requesting georeferenced map images from a server over HTTP. It returns pictures of data, not the data itself.

An Open Geospatial Consortium (OGC) standard for querying and retrieving geographic features, with geometry and attributes, from a server over the web.