Case Type Code
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.
Detailed Definition
A case type code identifies what kind of case a BLM record is. Every mining claim, mill site, and tunnel site recorded with BLM is a case in the Mineral & Land Records System (MLRS), and each case carries a type.
Where the codes come from
BLM's land records page says MLRS "has replaced and integrated many legacy BLM systems (e.g., LR2000, Alaska's ACRES/ALIS, LRAM, CSRC)" and manages cases across "mining claims, fluid minerals, geothermal energy, land tenure, solid minerals, land use authorizations, realty billing, and other case types." BLM's published MLRS mining claim datasets include a field named "Case Type Number" and a "BLM Product" name for each case.
Mining claim and site codes in BLM's published data
- 384101: Lode Claim
- 384103: Lode Claim - National Park
- 384201: Placer Claim
- 384203: Placer Claim - National Park
- 384301: Tunnel Site
- 384401: Mill Site
Surface management codes in BLM's published data
- 380913: Surface Management - Notice
- 380910: Surface Management Plan - Mining
- 380911: Surface Management Plan - Exploration
- 380912: Surface Management Plan - Ancillary
- 380210: Surface Management Plan Wilderness Review
These values are read from BLM's national MLRS feature services for mining claims, locatable notices, and plans of operations.
What the four types mean
The MLRS help center says there are "4 different types of mining claims/sites":
- Lode claim: "veins, ledges, or other rock in place; not to exceed 1500 ft. by 600 ft. or 20.66 acres"
- Placer claim: "rock not in original place (river sands or gravel); may not exceed 20 acres per individual claimant, up to 160 acres maximum"
- Mill site: "non-mineral land not contiguous to vein or lode," "not to exceed 5 acres"
- Tunnel site: "subsurface right-of-way used for access to lode claims or exploration of undiscovered lodes"
Why the type matters
- Fees. The maintenance fee is $200 per lode claim, mill site, or tunnel site, but $200 "for each 20 acres of the placer claim or portion thereof" (43 CFR 3830.21(d)).
- Annual filings. Under a small miner waiver, mining claims need an affidavit of assessment work, while mill and tunnel sites need a notice of intent to hold (43 CFR 3835.31(d)).
- Amendments. A notice or certificate of location may not be amended to "Change the type of claim or site" (43 CFR 3833.21(b)(3)).
- National park mining claims. A small miner waiver for mining claims on National Park System lands requires a plan of operations approved by the National Park Service before assessment work is done (43 CFR 3835.17(a)).
Why it matters in mining claim research
The case type is the first filter when pulling BLM records for an area. It separates lode claims from placer claims and sites, and it separates mining claims from the notices and plans that authorize work on them. A researcher checks the type against the recorded notice or certificate, since the fee owed and the filings required both follow from it.
Related Terms
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.
BLM State Office
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.
BLM Serial Number
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.
Disposition Code
The status BLM's Mineral & Land Records System (MLRS) gives a case, such as Active, Closed, Filed, Under Review, or On Appeal.
Land Status
The legal condition of a tract of federal land: ownership of surface and minerals, withdrawals, segregations, reservations, and the rights already attached to it.