generated: '2026-09-05'
method: derived
source: >-
  openapi/bureau-of-land-management-gbp-hub-search-openapi.json (47 component schemas),
  conformance/bureau-of-land-management-gbp-hub-ogc-collections.json,
  openapi/bureau-of-land-management-arcgis-service-inventory.json, and
  https://gbp-blm-egis.hub.arcgis.com/data.json — all read 2026-09-05.
note: |
  Two different data models sit behind BLM's public surface and they meet only at the item id.

  The CATALOG model (OGC API - Records) is about metadata: collections hold records, records
  point at services. The GEOSPATIAL model (ArcGIS) is about the data itself: services hold
  layers, layers hold fields and features. An agent that wants BLM's actual land data walks
  from the first into the second — search the catalog, read the record's geoservice link, then
  query the layer.

  Every entity below is present in a document BLM serves. Nothing is inferred from naming.
entities:
  - name: Catalog
    schema: Catalog
    surface: gbp-hub-search
    description: >-
      The site catalog definition — which ArcGIS groups and item types the BLM GBP Hub scopes
      itself to. One per hub site.
    identifier: the hub site item id (1f7469023a92437a8a7e2dd7d8ba808a for BLM GBP Hub)
  - name: Collection
    schema: CollectionDto
    surface: gbp-hub-search
    description: An OGC API - Records collection. BLM publishes three.
    identifier: id
    fields: [id, type, title, description, itemType, crs, filters]
    instances:
      - id: dataset
        title: Data
        itemType: record
        description: 'BLM GBP Hub: Data Collection'
      - id: document
        itemType: record
      - id: site
        itemType: record
    note: >-
      Instance list read from
      conformance/bureau-of-land-management-gbp-hub-ogc-collections.json. The `dataset`
      collection's filters[] enumerates the ArcGIS item types it admits — Feature Service,
      Feature Layer, Image Service, Table, CSV, GeoJSON, KML, Shapefile, File Geodatabase,
      Stream Service.
  - name: Record
    schema: OgcItemDto
    surface: gbp-hub-search
    description: >-
      One catalog record — a GeoJSON Feature whose properties carry the dataset metadata and
      whose geometry is the dataset extent.
    identifier: id (32-character ArcGIS item id)
    fields: [id, type, geometry, properties, time]
    count_observed: 803
  - name: Dataset
    schema: dcat:Dataset
    surface: dcat-us
    description: >-
      The same 803 datasets, expressed in the federal open-data vocabulary at
      https://gbp-blm-egis.hub.arcgis.com/data.json.
    identifier: identifier (an arcgis.com item URL)
    fields: [identifier, landingPage, title, description, keyword, issued, modified, publisher, contactPoint, distribution]
    note: publisher.name is "Bureau of Land Management" on every record.
  - name: FeatureService
    schema: FeatureServerDto
    surface: arcgis-rest
    description: An ArcGIS FeatureServer or MapServer. 785 exist across BLM's 13 REST instances.
    identifier: '<instance>/<folder>/<name>/<type>'
    counts:
      MapServer: 463
      FeatureServer: 283
      ImageServer: 16
      GPServer: 12
      SymbolServer: 10
      GeometryServer: 1
  - name: FeatureLayer
    schema: FeatureLayerFieldDto (fields), FeatureInfoDto
    surface: arcgis-rest
    description: A layer inside a service. 261 layers across the 46 national services alone.
    identifier: layerIndex within its service
    fields: [id, name, type, geometryType, fields, maxRecordCount, extent, spatialReference]
  - name: Field
    schema: FeatureLayerFieldDto
    surface: arcgis-rest
    description: One attribute column on a layer.
    fields: [name, type, alias, sqlType, domain, defaultValue, length, editable, nullable]
  - name: WMSLayer
    schema: WMS 1.3.0 Layer element
    surface: ogc-wms
    description: >-
      The same layers projected as OGC WMS layers, described in the GetCapabilities documents
      saved verbatim in openapi/.
    identifier: Layer/Name
relationships:
  - from: Catalog
    to: Collection
    type: has_many
    via: links[rel=data]
  - from: Collection
    to: Record
    type: has_many
    via: links[rel=items]
  - from: Record
    to: Record
    type: has_many
    via: /items/{recordId}/related
    note: >-
      Explicit relationship traversal. /items/{recordId}/connected is a second, distinct edge
      type on the same entity.
  - from: Record
    to: FeatureService
    type: has_one
    via: 'rest/services/collections/{collectionId}/geoservice/FeatureServer'
    note: >-
      This is the join that matters. It is how an agent gets from "I found the grazing allotment
      dataset" to "I can query its geometry".
  - from: Record
    to: Dataset
    type: has_one
    via: the shared ArcGIS item id
    note: >-
      The OGC record and the DCAT-US dataset are two serializations of one item. The DCAT
      identifier is an arcgis.com item URL whose id parameter equals the OGC record id.
  - from: FeatureService
    to: FeatureLayer
    type: has_many
    via: layers[]
  - from: FeatureLayer
    to: Field
    type: has_many
    via: fields[]
  - from: FeatureLayer
    to: WMSLayer
    type: has_one
    via: the WMSServer projection of the same MapServer
    note: Only for the 42 of 46 national services that advertise the WMSServer extension.
identifier_conventions:
  - entity: Record / Dataset
    form: 32-character lowercase hexadecimal ArcGIS item id
    example_shape: 023d2b2d882046fdb84e00983cfe636e
  - entity: FeatureService
    form: 'folder/ServiceName/ServiceType, case-sensitive'
    example_shape: lands/BLM_Natl_SMA_Cached_without_PriUnk/MapServer
    note: >-
      BLM's own naming convention is legible and worth knowing: BLM_Natl_* is a national
      dataset, BLM_<ST>_* is state-specific, BOC_* is a boundary reference layer, and *_Cached
      is a pre-rendered tile service.
domains:
  - lands (surface management agency, NLCS, ACEC, land use planning, LPAD/PLAD)
  - Cadastral (PLSS CadNSDI, in two datums)
  - recreation (recreation sites and facilities, MAPLand, mountain biking, visual resources)
  - range (grazing allotments and pastures, wild horse and burro)
  - transportation (ground transportation linear features)
  - admin_boundaries (BLM administrative units and offices, county boundaries)
  - geophysical (paleontological potential, geologic formations)
  - elevation (3DEP lidar priority areas)
  - vegetation, wildlife, fire, DANL, PCPL
render: null