{
  "claims": [],
  "entities": [],
  "history": [
    {
      "action": "ADD",
      "change_set_id": "wp-20260926-yosemite-valley-route-graph",
      "evidence_refs": [],
      "knowledge_gap_refs": [],
      "path": "canonical/v0/sources/source-nps-yosemite-four-mile-trail-2026.json",
      "reason": "Add reviewed Yosemite Valley route topology from official NPS route descriptions and trail geometry.",
      "record_id": "source-nps-yosemite-four-mile-trail-2026",
      "record_type": "source",
      "summary": "Add bidirectional reviewed segment topology for Four Mile Trail, Yosemite Falls Trail, and the Happy Isles to Nevada Fall JMT/Mist network, while preserving unresolved Valley graphs as a gap."
    }
  ],
  "navigation": {
    "next_id": "source-nps-yosemite-glacier-point",
    "position": 234,
    "previous_id": "source-nps-yosemite-fees",
    "total": 587
  },
  "observations": [
    {
      "artifact_refs": [],
      "content": "NPS states that Four Mile Trail begins along Southside Drive and climbs 4.8 miles one way to Glacier Point; it can be reversed or combined with Panorama Trail.",
      "observation_id": "observation-nps-yosemite-four-mile-trail-20260926",
      "observed_at": null,
      "observer": "",
      "retrieved_at": "2026-09-26T00:00:00+00:00",
      "source_id": "source-nps-yosemite-four-mile-trail-2026"
    }
  ],
  "record": {
    "locator": "https://www.nps.gov/yose/planyourvisit/fourmiletrail.htm",
    "publisher": "National Park Service",
    "source_id": "source-nps-yosemite-four-mile-trail-2026"
  },
  "record_type": "source",
  "related_records": [],
  "sources": [
    {
      "locator": "https://www.nps.gov/yose/planyourvisit/fourmiletrail.htm",
      "publisher": "National Park Service",
      "source_id": "source-nps-yosemite-four-mile-trail-2026"
    }
  ]
}