Every time you tap a claim block in a BLM GIS tool or in AuthoriProspector, you're looking at data that comes directly from the MLRS database. The field names look like arcane abbreviations — CSE_DISP, RCRD_ACRS, PLSS_DESC — but each one tells you something specific and actionable. Once you can read a raw MLRS record, you can evaluate a claim target in under 60 seconds.
| Field | Full Name | What It Tells You |
|---|---|---|
| CSE_NR | Case Number | The unique identifier for this claim in the federal system. Use this to look up the claim in BLM LR2000 for full documentation. |
| CSE_DISP | Case Disposition | "Active" = maintained and valid. "Filed/Pending/Submitted" = in-process. "Closed" = forfeited or withdrawn — ground is open. |
| RCRD_ACRS | Recorded Acres | The acreage as recorded on the Notice of Location. Should be ≤20 for individual placer, ≤160 for association placer. |
| PLSS_DESC | PLSS Description | The aliquot notation (e.g. N2NWNE) identifying the 20-acre parcel within its section. Read right-to-left. |
| LOC_DT | Location Date | The date the claim was physically located and monumented. This is the priority date for competing claims. |
| LST_ASMT_YR | Last Assessment Year | The most recent year the annual maintenance fee was paid. A year more than 1 behind current = potential forfeiture risk. |
| CSTMRNM | Customer Name | The recorded claim holder name — individual or company. Privacy-filtered in some public interfaces. |
| MRG_ACRS | Meridian/Group Acres | Administrative grouping field. Not typically used for prospecting decisions. |
The disposition field is the first thing to check. "Active" means the claim is valid and the annual fee is current. "Filed" generally means the initial paperwork is in but the BLM processing isn't complete. "Pending" and "Submitted" are similar transitional states. "Closed" is what you're looking for when identifying open ground — it means the claim has been forfeited, withdrawn, or otherwise terminated.
If you're investigating a contested area where two claims appear to overlap, the location date (LOC_DT) determines priority. The earlier location date wins, assuming both claims were properly recorded. Note that LOC_DT is the date of physical location in the field — not the county recording date or the BLM filing date. Those come later in the process.
The last assessment year is updated each time the BLM records an annual maintenance fee payment for the claim. If you're looking at a claim in 2026 and the LST_ASMT_YR is 2023, that claim has been delinquent for two years. It should already have been forfeited — check with the BLM to confirm whether it has been officially closed in the system.
AuthoriProspector overlays live BLM claims, 20-acre aliquot precision, USGS historic mine markers, and no-go zones on a single map. Tap any block to see who owns it — then stake and file from the field.
View BLM Claim Records on AuthoriProspector →