MountainSwitch Know before you go.

Search and menu

Search for a destination, or browse routes, system status, documentation, and legal links.

Areas
Lake TahoeSouthern California MountainsEastern SierraCentral SierraYosemite & Southern Sierra
Area
Area All areas
Activity
Activity Any activity

PLAN YOUR TRIP

ABOUT THIS SITE

Developers

Destination access

Overview

GET

/v1/destinations/:destination/access

Destination access

Destination access is the primary access-answer endpoint for agent flows. Use it after destination discovery when the caller needs a destination-level verdict, path coverage, and the reason behind the current answer.

Direction-aware segments keep the arrival-oriented answer separate from disclosure: arrival_direction names travel toward the destination, while restriction_items[].direction names the flow affected by each disclosed source row.

Parameters

Path and query parameters are documented together so the request surface stays easy to scan.

destination

Path Required

string

Canonical destination slug from GET /v1/destinations with endpoints.access set to true. Use an access-capable slug such as big-bear, mammoth-lakes, dodge-ridge, or bear-valley. Unknown or non-access slugs return 404 DESTINATION_NOT_FOUND.

jurisdiction

Query Optional

string

Optional for the active California v1 surface. If omitted, the effective jurisdiction defaults to US-CA. If provided, it must canonicalize to US-CA or the request returns INVALID_PARAMETER or INVALID_JURISDICTION.

Example request

Use the same endpoint across all three snippets. The tabs switch only the client syntax.

cURL

 
curl -sS "https://api.mountainswitch.co/v1/destinations/big-bear/access?jurisdiction=US-CA" \
  -H "Accept: application/json"

Example response

The example response shows the documented JSON envelope with endpoint data in data and request metadata in _meta.

200 OK application/json 
{
  "data": {
    "destination": "big-bear",
    "jurisdiction": "US-CA",
    "coverage": "full",
    "access_state": "restricted",
    "reason_excerpt": "Chains or traction devices are required on SR-330.",
    "paths": [
      {
        "id": "ca:big-bear:west_via_330_18",
        "label": "West approach via SR-330 and SR-18",
        "role": "primary",
        "coverage": "full",
        "access_state": "restricted",
        "reason_excerpt": "Chains or traction devices are required on SR-330.",
        "segments": [
          {
            "id": "ca:big-bear:sr330_highland_to_running_springs",
            "route": "SR-330",
            "route_slug": "sr-330",
            "label": "Highland to Running Springs",
            "role": "primary",
            "start_boundary_label": "Highland",
            "end_boundary_label": "Running Springs",
            "coverage": "full",
            "access_state": "restricted",
            "reason_excerpt": "Chains or traction devices are required from Highland to Running Springs.",
            "segment_description": null,
            "type_of_closure": null,
            "type_of_work": null,
            "lanes_closed": null,
            "total_existing_lanes": null,
            "estimated_delay_minutes": null,
            "valid_until": "2026-04-15T18:00:00Z",
            "chain_control_severity": 3,
            "chain_control_raw": "R-2",
            "restriction_items": [
              {
                "reason_excerpt": "Chains or traction devices are required from Highland to Running Springs.",
                "direction": "both",
                "segment_description": null,
                "type_of_closure": null,
                "type_of_work": null,
                "lanes_closed": null,
                "total_existing_lanes": null,
                "estimated_delay_minutes": null,
                "valid_until": "2026-04-15T18:00:00Z",
                "chain_control_severity": 3,
                "chain_control_raw": "R-2"
              }
            ]
          },
          {
            "id": "ca:big-bear:sr18_running_springs_to_big_bear",
            "route": "SR-18",
            "route_slug": "sr-18",
            "label": "Running Springs to Big Bear Dam",
            "role": "primary",
            "start_boundary_label": "Running Springs",
            "end_boundary_label": "Big Bear Dam / SR-38 junction",
            "coverage": "full",
            "access_state": "open",
            "reason_excerpt": null,
            "segment_description": null,
            "type_of_closure": null,
            "type_of_work": null,
            "lanes_closed": null,
            "total_existing_lanes": null,
            "estimated_delay_minutes": null,
            "valid_until": null,
            "chain_control_severity": null,
            "chain_control_raw": null,
            "restriction_items": []
          }
        ]
      },
      {
        "id": "ca:big-bear:east_via_38",
        "label": "East approach via SR-38",
        "role": "alternate",
        "coverage": "full",
        "access_state": "restricted",
        "reason_excerpt": "One lane is closed on SR-38 approaching Big Bear Valley.",
        "segments": [
          {
            "id": "ca:big-bear:sr38_redlands_to_big_bear",
            "route": "SR-38",
            "route_slug": "sr-38",
            "label": "Redlands / Mentone to Big Bear Valley",
            "role": "alternate",
            "start_boundary_label": "Redlands / Mentone",
            "end_boundary_label": "Big Bear Valley",
            "coverage": "full",
            "access_state": "restricted",
            "reason_excerpt": "One lane is closed on SR-38 approaching Big Bear Valley.",
            "segment_description": "SR-38 approaching Big Bear Valley",
            "type_of_closure": "Lane closure",
            "type_of_work": "Emergency work",
            "lanes_closed": 1,
            "total_existing_lanes": 2,
            "estimated_delay_minutes": 20,
            "valid_until": "2026-04-15T20:00:00Z",
            "chain_control_severity": null,
            "chain_control_raw": null,
            "restriction_items": [
              {
                "reason_excerpt": "One lane is closed on SR-38 approaching Big Bear Valley.",
                "direction": "E",
                "segment_description": "SR-38 approaching Big Bear Valley",
                "type_of_closure": "Lane closure",
                "type_of_work": "Emergency work",
                "lanes_closed": 1,
                "total_existing_lanes": 2,
                "estimated_delay_minutes": 20,
                "valid_until": "2026-04-15T20:00:00Z",
                "chain_control_severity": null,
                "chain_control_raw": null
              }
            ]
          },
          {
            "id": "ca:big-bear:sr18_greenway_to_big_bear",
            "route": "SR-18",
            "route_slug": "sr-18",
            "label": "Big Bear City to Big Bear Valley",
            "role": "connector",
            "start_boundary_label": "Big Bear City",
            "end_boundary_label": "Big Bear Valley",
            "coverage": "full",
            "access_state": "open",
            "reason_excerpt": null,
            "segment_description": null,
            "type_of_closure": null,
            "type_of_work": null,
            "lanes_closed": null,
            "total_existing_lanes": null,
            "estimated_delay_minutes": null,
            "valid_until": null,
            "chain_control_severity": null,
            "chain_control_raw": null,
            "restriction_items": []
          }
        ]
      }
    ]
  },
  "_meta": {
    "sources": [
      {
        "source": "ca-d8-chain-controls",
        "freshness": "healthy",
        "live_eligible": true,
        "covers_query": true,
        "source_updated_at": "2026-04-15T16:50:00Z",
        "fetched_at": "2026-04-15T16:55:00Z"
      },
      {
        "source": "ca-d8-lane-closures",
        "freshness": "healthy",
        "live_eligible": true,
        "covers_query": true,
        "source_updated_at": "2026-04-15T16:45:00Z",
        "fetched_at": "2026-04-15T16:55:00Z"
      }
    ],
    "query_coverage": "full",
    "request_id": "req_destination_access_docs",
    "response_generated_at": "2026-04-15T17:00:00Z",
    "pagination": null
  }
}

Response fields

This reference stays flat on purpose so the documented fields remain easy to scan.

destination
string
Canonical destination slug for the requested access answer.
jurisdiction
string
Canonical jurisdiction code. For the active California v1 surface, this resolves to US-CA.
coverage
"full" | "partial" | "none"
Destination-level aggregation coverage across the destination's known access paths.
access_state
"open" | "advisory" | "restricted" | "closed" | null"
Destination-level answer. When coverage is insufficient for a confident answer, this becomes null instead of synthesizing open.
reason_excerpt
string | null
Compact explanation for the current destination, path, or segment answer. Open and unknown answers return null.
paths
Array<object>
Ordered access paths for the destination, each with its own coverage, access_state, and segment detail.
paths[].segments[].route_slug
string
Stable route slug for the segment's route, such as sr-330 or sr-38.
paths[].segments[].arrival_direction
"N" | "S" | "E" | "W" | omitted
Optional normalized direction of travel toward the destination across this segment. The property is absent unless the access registry affirms an arrival orientation.
paths[].segments[].start_boundary_label
string
Human-readable start boundary for the segment.
paths[].segments[].end_boundary_label
string
Human-readable end boundary for the segment.
paths[].segments[].segment_description
string | null
Winner-row descriptive text for the segment when a matched restriction or work row provides it.
paths[].segments[].type_of_closure
string | null
Closure type from the winner row when lane-closure detail exists.
paths[].segments[].type_of_work
string | null
Work classification from the winner row when present.
paths[].segments[].lanes_closed
number | null
Closed-lane count from the gated winner row when lane-closure detail exists. Disclosure-only rows remain available under restriction_items.
paths[].segments[].total_existing_lanes
number | null
Total lane count paired with lanes_closed when the matched row provides it.
paths[].segments[].estimated_delay_minutes
number | null
Delay estimate from the matched lane-closure row when available.
paths[].segments[].valid_until
string | null
ISO timestamp for the winner row's current validity window when the source provides one.
paths[].segments[].chain_control_severity
number | null
Additive chain-control severity for the segment winner row. Lane-closure-backed rows may legally return null.
paths[].segments[].chain_control_raw
string | null
Raw chain-control code for the segment winner row when chain-control data is present.
paths[].segments[].restriction_items
Array<object>
Disclosure-complete structured detail for every matched non-open persisted row on the segment. Admitted rows are ordered before direction-excluded rows, so an item may remain disclosed without driving access_state. This field is always present and becomes [] when no live-eligible non-open rows match.
paths[].segments[].restriction_items[].direction
"N" | "S" | "E" | "W" | "both" | null
Normalized travel direction affected by this disclosed row. When arrival_direction is affirmed, an exactly opposite full-coverage Mainline or Conventional Hwy lane row remains disclosed here but is excluded from the segment winner.
paths[].segments[].restriction_items[].chain_control_severity
number | null
Per-row additive chain-control severity mirrored directly from the matched persisted restriction item.
paths[].segments[].restriction_items[].chain_control_raw
string | null
Per-row additive chain-control code mirrored directly from the matched persisted restriction item.
_meta.sources
Array<object>
Current adapter coverage records for the destination scope, ordered by source ascending.
_meta.query_coverage
"full" | "partial" | "none"
Endpoint-wide source coverage signal. Check this before treating the destination answer as fully verified.
_meta.request_id
string
Request identifier for debugging and support workflows.
_meta.response_generated_at
string
ISO timestamp describing when the API assembled the response.
_meta.pagination
null
Always null because destination access is a non-paginated data endpoint.

Errors

These rows keep the repo-wide rate-limit and infrastructure behavior visible without inventing endpoint-specific transport semantics.

Status Code When it happens
400 INVALID_PARAMETER The request contains a repeated or unrecognized query parameter, or jurisdiction resolves to a known code other than US-CA.
400 INVALID_JURISDICTION The provided jurisdiction value does not canonicalize to a known jurisdiction code.
404 DESTINATION_NOT_FOUND The destination slug is unknown or unsupported for the requested jurisdiction.
429 RATE_LIMIT_EXCEEDED The caller exceeded the shared API rate limit.
503 SERVICE_UNAVAILABLE D1 or another critical dependency is unavailable. Source coverage gaps remain HTTP 200 with query_coverage instead of switching to 503.

Notes

These notes capture the contract edges that matter most for consumers of the endpoint.

Use destination access for the primary answer

Start with GET /v1/destinations to find the canonical slug and inspect endpoint markers. When endpoints.access is true, use destination access before route summary or raw conditions for the destination-level reachability answer.

Coverage describes confidence, not just freshness

Check _meta.query_coverage, source freshness, source live_eligible, and the per-object coverage values for destination, path, and segment rows. Stale-but-usable sources may still support an access answer. When coverage is partial or none, access_state can be null and clients must not synthesize open.

Direction separates the access answer from full disclosure

When arrival_direction is present, clients can read it as the direction of travel toward the destination. restriction_items[].direction describes the travel flow affected by each disclosed row. Do not infer that every restriction_items entry drove access_state; use the segment's singular fields for the gated winner and restriction_items for the complete matched disclosure.

Only full coverage responses are cacheable

This endpoint follows the fresh-full-only cache posture. The API caches responses only when _meta.query_coverage is full and every covering source is below the stale threshold. Stale-but-usable, partial, and none responses are no-store and should be treated as uncached live reads.