# Bureau of Land Management > The Bureau of Land Management (BLM) is the US Department of the Interior bureau that > administers 245 million surface acres and 700 million acres of subsurface mineral estate — > roughly one in every ten acres of the United States. Its public API surface is entirely > geospatial and entirely anonymous: a catalog of 803 datasets served as OGC API - Records and > DCAT-US, and 785 ArcGIS Server services across 13 REST instances that BLM operates itself on > gis.blm.gov. There is no API key, no plan, no quota and no rate limit — and equally no > versioning policy, no changelog, no status page and no support channel. Every operation is > read-only. Generated by API Evangelist, 2026-09-05. BLM publishes no llms.txt of its own (https://www.blm.gov/llms.txt returned HTTP 404 on 2026-09-05). ## Start here - [GIS Data](https://www.blm.gov/services/geospatial/GISData): BLM's own page on how to reach its geospatial data. The closest thing to a developer landing page that exists. - [BLM GBP Hub](https://gbp-blm-egis.hub.arcgis.com/): the Geospatial Business Platform hub — search, maps, downloads, and the OGC API behind them. - [ArcGIS REST services directory](https://gis.blm.gov/arcgis/rest/services): the national ArcGIS Server catalog. Add `?f=json` for machine-readable output; HTML is the default. ## Machine-readable contracts - [BLM GBP Hub Search API (OpenAPI 3.0.0)](https://gbp-blm-egis.hub.arcgis.com/api/search/definition/?f=json): 17 operations, OGC API - Records. The only OpenAPI BLM serves. - [OGC conformance](https://gbp-blm-egis.hub.arcgis.com/api/search/v1/conformance): declares OGC API Common 1.0/2.0, Features 1.0 (core, geojson, oas30) and Records 1.0. - [Collections](https://gbp-blm-egis.hub.arcgis.com/api/search/v1/collections): dataset, document, site. - [WMS 1.3.0 GetCapabilities (Surface Management Agency)](https://gis.blm.gov/arcgis/services/lands/BLM_Natl_SMA_Cached_without_PriUnk/MapServer/WMSServer?service=WMS&request=GetCapabilities): 42 of the 46 national services publish one of these. The GetCapabilities document IS the contract — there is no OpenAPI for the ArcGIS surface. - [WMS 1.3.0 GetCapabilities (PLSS CadNSDI)](https://gis.blm.gov/arcgis/services/Cadastral/BLM_Natl_PLSS_CadNSDI/MapServer/WMSServer?service=WMS&request=GetCapabilities): the Public Land Survey System, the cadastral fabric most third-party land tools are built on. ## Bulk data - [DCAT-US 1.1 catalog](https://gbp-blm-egis.hub.arcgis.com/data.json): 803 datasets, 4.8 MB, conforms to the federal Project Open Data v1.1 schema. Every record carries `issued` and `modified` — the only machine-readable change signal this provider emits. - [DCAT-AP 2.1.1 catalog](https://gbp-blm-egis.hub.arcgis.com/api/feed/dcat-ap/2.1.1.json) - [GeoRSS feed](https://gbp-blm-egis.hub.arcgis.com/api/feed/rss/2.0) - [BLM datasets on data.gov](https://catalog.data.gov/dataset?organization=blm-gov) ## The 13 ArcGIS REST instances All ArcGIS Server 11.5, all anonymous (`isTokenBasedSecurity: false`), 785 services in total. - National, 46 services: https://gis.blm.gov/arcgis/rest/services - Alaska 59: https://gis.blm.gov/akarcgis/rest/services - Arizona 24: https://gis.blm.gov/azarcgis/rest/services - California 40: https://gis.blm.gov/caarcgis/rest/services - Colorado 100: https://gis.blm.gov/coarcgis/rest/services - Eastern States 2: https://gis.blm.gov/esarcgis/rest/services - Idaho 146: https://gis.blm.gov/idarcgis/rest/services - Montana 23: https://gis.blm.gov/mtarcgis/rest/services - Nevada 50: https://gis.blm.gov/nvarcgis/rest/services - New Mexico 41: https://gis.blm.gov/nmarcgis/rest/services - Oregon 85: https://gis.blm.gov/orarcgis/rest/services - Utah 51: https://gis.blm.gov/utarcgis/rest/services - Wyoming 118: https://gis.blm.gov/wyarcgis/rest/services ## Other BLM systems - [Mineral and Land Records System (MLRS)](https://mlrs.blm.gov/s/): mining claims, land patents, rights-of-way. Salesforce Experience Cloud on a blm.gov host. Serves an OIDC discovery document anonymously; every other path returns 401. No public contract. - [General Land Office Records](https://glorecords.blm.gov/default.aspx): federal land conveyance records, patents, survey plats and field notes from 1788. Same platform, same posture — OIDC discovery public, everything else 401. - [ePlanning](https://eplanning.blm.gov/): NEPA planning documents and public comment. Microsoft Power Pages. No public API. ## Things an agent must know - **Two of the three surfaces return HTTP 200 on failure.** `gis.blm.gov` answers 200 with `{"error":{"code":404,...}}`; WMS answers 200 with an XML `ServiceExceptionReport`. Only the GBP Hub Search API sets an honest 4xx. Branch on the body, not the status line. - **Send `f=json`.** ArcGIS defaults to HTML. - **The API is read-only.** No write operation exists on any public surface, so idempotency and reversibility do not apply. - **`limit` on the search API is capped at 20000**; validation errors return `message` as an array, not a string. ArcGIS layers cap results at their own per-layer `maxRecordCount`. - **No rate limits are published and no rate-limit headers are returned.** There is no runtime signal telling you how hard you may push. - **No versioning or deprecation policy exists.** `currentVersion: 11.5` on the ArcGIS instances is the Esri product version, not a contract version. ## Security and policy - [security.txt](https://www.blm.gov/.well-known/security.txt) (RFC 9116) - [Vulnerability disclosure policy](https://www.blm.gov/info/notices/vulnerability-disclosure) - [BLM vulnerability disclosure programme on Bugcrowd](https://bugcrowd.com/engagements/blm-vdp) - [Privacy policy (DOI)](https://www.doi.gov/privacy) - [Disclaimer (DOI)](https://www.doi.gov/disclaimer) - [Website disclaimers](https://www.blm.gov/info/notices) ## Code and contact - [DOI-BLM on GitHub](https://github.com/DOI-BLM): source only — no packages are published to npm, PyPI or any other registry. - [Contact BLM](https://www.blm.gov/contact) — general agency contact. There is no developer support channel. - [Our Stories (BLM blog)](https://www.blm.gov/blog) ## Licensing BLM geospatial data is United States federal public-domain public record. See https://www.doi.gov/disclaimer.