Recreation.gov Availability Check

Purpose

Given a Recreation.gov bookable resource — campground, backcountry permit, lottery, timed-entry tour, or day-use site — plus a date range and an optional filter surface, return the per-site (or per-division) per-day availability matrix. Resolves names → facility IDs via Recreation.gov's public-but-undocumented JSON API, then pulls structured per-day status, equipment caps, accessibility, pet policy, fees, photos, and canonical site URLs.

Read-only — never click Reserve, Add to Cart, Add to Lottery, Apply, or Proceed to Payment.

When to Use

• "Is Upper Pines open for tents 6/15–6/19?" — campground availability lookups.
• "When does the Half Dome daily-permit lottery draw next, and how many slots remain post-draw?" — backcountry permit + lottery.
• "Any Wave Coyote Buttes North permits left in June 2026?" — daily-lottery + advanced-lottery permits.
• "Mariposa Grove shuttle tickets for next Saturday morning?" — timedentry / timedentry_tour ticketing.
• Any scraper / agent that previously rendered the React SPA to read availability — replace with the JSON path below for a ~100× speed-up.

Workflow

Recreation.gov ships a public-but-undocumented JSON API that backs every page of the React SPA. There is no auth, no cookies, no CSRF token, and no anti-bot challenge on the read endpoints used below — verified against /api/search, /api/search/suggest, /api/camps/availability/campground/{id}/month, /api/camps/availability/campsite/{id}/all, /api/camps/campsites/{id}, /api/camps/campgrounds/{id}, /api/permits/{id}/availability, /api/permitcontent/{id}, and /api/timedentry/availability/facility/{id} (2026-05-18, no proxies, no stealth, no Referer, default browser-shaped UA — all returned 200 with full payload). Lead with the JSON path; only fall back to scripted browsing if Recreation.gov rolls anti-bot onto these endpoints (not observed today, but they reserve the right to gate hot-launch moments — see Gotchas).

Step 1 — Resolve the input to a typed entity_id

Skip if the caller already gave a /camping/campgrounds/{id}, /permits/{id}, or /ticket/facility/{id} URL — parse the trailing integer and the path segment, which maps directly to the entity_type used below:

Otherwise resolve a free-text name (and optional state) through the suggest index:

GET https://www.recreation.gov/api/search/suggest?q={URL-encoded name}&geocoder=true

Returns inventory_suggestions[] with entity_id, entity_type, name, parent_name, state_code (full state name — "California", not "CA"), preview_image_url, and reservable: bool. Filter client-side on state if needed — the documented fq=state_code:"CA" filter on /api/search gets HTML-entity-encoded by the gateway and returns total: 0. Stick with suggest + client-side filter.

For permit/lottery lookups, the verbose /api/search?q=...&entity_type=permit endpoint returns richer cards (camping-equipment-allowed lists, average rating, accessible-campsite counts, mailing/physical addresses) — only call it when you actually need those extra fields. Both endpoints share the same entity_id namespace.

Step 2 — Pull availability based on entity_type

A. Campgrounds (entity_type: "campground")

Two endpoint shapes — pick by the shape of the question.

A1. "What's available across all sites in this campground for these dates?" — the per-facility, per-month endpoint:

GET https://www.recreation.gov/api/camps/availability/campground/{facilityId}/month
    ?start_date=YYYY-MM-01T00%3A00%3A00.000Z

• start_date must be the first of a month in YYYY-MM-01T00:00:00.000Z form. Any other day returns 400 {"error":"Only the first of the month is allowed for this request"}. To cover a multi-month range, loop month-by-month and concatenate campsites[*].availabilities keys.
• Returns {campsites: {{campsite_id}: {site, loop, campsite_type, campsite_reserve_type, availabilities: {date: status}, quantities, min_num_people, max_num_people, type_of_use}}, count}. Upper Pines (232447) returns 235 sites at ~490 KB per month.
• availabilities[date] values from this endpoint: "Available", "Reserved", "Closed", "Not Reservable", "Not Available", "Open", "Walk-up". Verified observed in this endpoint shape during sampling: Available, Reserved, Closed.

A2. "What are the next 18 months of availability for one specific site?" — the per-campsite endpoint:

GET https://www.recreation.gov/api/camps/availability/campsite/{campsiteId}/all

• Returns ~603 days of availability for one site (≈ 18 months forward from today). Cheaper than month-looping when you only care about one or a handful of sites.
• Status enum is DIFFERENT here: values observed are "Open", "Reserved", "Closed", "NYR" (Not Yet Released — the future booking window hasn't opened yet). Map "Open" → "Available" and "NYR" → "Not Reservable" when normalizing across both endpoints.

B. Permits / lotteries (entity_type: "permit")

GET https://www.recreation.gov/api/permits/{permitId}/availability
    ?start_date=YYYY-MM-DDT00%3A00%3A00.000Z
    &end_date=YYYY-MM-DDT00%3A00%3A00.000Z
    &commercial_acct=false
    &is_lottery=false

• Returns {payload: {permit_id, next_available_date, availability: {{division_id}: {date_availability: {date: {total, remaining, show_walkup, is_secret_quota}}}}}}.
• remaining is the post-lottery walk-up quota for daily-permit systems (Half Dome, Wave Daily). is_secret_quota: true means the API hides the exact number — surface as remaining: null, is_secret_quota: true rather than guessing.
• is_lottery=true flips the response to lottery-draw quotas (pre-draw applied-count, lottery_close_date, lottery_draw_date) for advanced-lottery permits like Wave Advanced (274309) and Half Dome's Seasonal division.

Fetch division metadata (names like "Half Dome Cables (Daily)", "Scenic", "Educational", accessibility flags, entry/exit points, per-division fees) from /api/permitcontent/{permitId} — the payload.divisions map is keyed by the same division_id returned in the availability response. The same payload exposes has_lottery: bool, the lotteries[] array of past/current lottery instances (one with is_active: true, executed: false is the next draw), and important_dates[].

C. Tours / day-use timed entry (entity_type: "timedentry" or "timedentry_tour")

GET https://www.recreation.gov/api/timedentry/availability/facility/{facilityId}
    ?date=YYYY-MM-DD

• One date per request. Loop client-side for a range. Bare YYYY-MM-DD only — passing YYYY-MM-DDT00:00:00.000Z returns 400 {"error":"strconv.Atoi: parsing \"01T00:00:00.000Z\": invalid syntax"}.
• Returns an array of tour-time slots with inventory_count.{ANY,COMM,FIT,LOTTERY,WALKUP} and matching reservation_count.* — available count = inventory_count.ANY − reservation_count.ANY. Also surfaces booking_windows.PRIMARY.{open_timestamp, close_timestamp} (the visibility window relative to wall time) and booking_window_open_override when the agency has shifted the release time.
• The legacy /api/ticket/... paths in older docs return 404 or empty arrays — use /api/timedentry/....

Step 3 — Enrich with per-site metadata

For each campsite_id you decide to surface, hit:

GET https://www.recreation.gov/api/camps/campsites/{campsiteId}

Returns under campsite.*:

• campsite_name (the public site number, e.g. "040"), loop, campsite_type ("RV NONELECTRIC", "STANDARD NONELECTRIC", "TENT ONLY NONELECTRIC", etc.), is_accessible (the ADA flag),
• permitted_equipment[] (e.g. [{equipment_name: "RV", max_length: 20}, {equipment_name: "Pop up", max_length: 18}]) — max_length is in feet,
• attributes[] of {attribute_code, attribute_value} pairs — pull pets_allowed, max_num_people, max_num_vehicles, max_vehicle_length, driveway_length, site_length,
• site_details_map.{campfire_allowed, capacity_rating, checkin_time, checkout_time, ...} for the summary card,
• notices[] with notice_type: "info" | "warning" — booking caveats the agency surfaces in the UI (HTML-escaped; un-escape < before display),
• campsite_latitude / campsite_longitude for the map pin.

For facility-level metadata (the campground's name, address, phone, time zone, alternate_names, cancellation_description, attached links[] of photos):

GET https://www.recreation.gov/api/camps/campgrounds/{facilityId}

Step 4 — Apply caller-side filters

The API does not accept filter params on the availability endpoints — apply group_size / site_type / equipment / ADA / pet / loop filters by post-filtering the campsite list against the metadata in step 3.

Step 5 — Construct canonical URLs

campground site:        https://www.recreation.gov/camping/campsites/{campsite_id}
campground facility:    https://www.recreation.gov/camping/campgrounds/{facility_id}
permit:                 https://www.recreation.gov/permits/{permit_id}
permit booking:         https://www.recreation.gov/permits/{permit_id}/registration/detailed-availability?type=overnight-permit
tour / timedentry:      https://www.recreation.gov/ticket/facility/{facility_id}
tour booking tour:      https://www.recreation.gov/ticket/{facility_id}/ticket/{tour_id}

Browser fallback

The React SPA at /camping/campgrounds/{id} paints the same data the JSON path returns, but every read costs ~1 MB of JS download + ~3 s rendering, the calendar grid is virtualized (must scroll to materialize off-screen weeks), and per-site detail requires opening a modal per click. The JSON path is ~100× faster and dollar-cheaper. Only fall back if Recreation.gov starts gating the API endpoints (in which case: open a Browserbase session with --advanced-stealth --proxies because the JS bundle and /api/* calls then go through Akamai's challenge layer; the public read endpoints listed above do not require it today).

Site-Specific Gotchas

• start_date must be the 1st of a month on /api/camps/availability/campground/{id}/month. Server returns 400 {"error":"Only the first of the month is allowed for this request"} for any other day. Multi-month range queries must loop month-by-month and concatenate.
• The status enum differs between /month and /campsite/.../all. /month emits Available | Reserved | Closed | Not Reservable | Not Available | Open | Walk-up. /campsite/{id}/all emits Open | Reserved | Closed | NYR. Always normalize when merging the two: Open → Available, NYR → Not Reservable (the future booking window hasn't opened yet). A naïve consumer that only knows Available will treat valid future inventory as unavailable.
• Tour / timedentry availability is one date per request. /api/timedentry/availability/facility/{id}?date=YYYY-MM-DD — bare YYYY-MM-DD, no ISO suffix. Passing 2026-06-01T00:00:00.000Z returns 400 strconv.Atoi parsing "01T00:00:00.000Z". The legacy /api/ticket/... paths return 404 or empty — they were superseded.
• is_lottery=true vs is_lottery=false are different views of the same permit. False returns the post-draw walk-up quota stream (daily walk-up flag + remaining). True returns the pre-draw applied-count / lottery_close_date / lottery_draw_date. For permits with both (Half Dome: daily walk-up plus a separate seasonal lottery division), call both shapes and merge by division_id.
• is_secret_quota: true means the API hides remaining. Don't infer remaining: 0 — it's "the agency declines to publish the number." Surface remaining: null, is_secret_quota: true.
• reservable: false in /api/search/suggest. Some entities (boundary-only recarea entries, decommissioned facilities) come back with reservable: false — skip them before hitting any availability endpoint or you'll get an empty-payload 200.
• /api/search?q=...&fq=state_code:"CA" is HTML-entity-encoded by the gateway: the response echoes fq:["state_code:"CA""] and silently returns total: 0. Either drop the fq and filter client-side on state_code (which is the full state name, e.g. "California", not the ISO code "CA"), or use /api/search/suggest which doesn't accept fq at all.
• /api/tours/{id} returns the React SPA HTML, not JSON. That route is a client-side React path, not an API. Use /api/timedentry/availability/facility/{id} for tour-shaped facilities.
• facility_id ≠ legacy_id ≠ parent_asset_id ≠ campsite_id. The /api/search results expose entity_id (which is the facility_id for campgrounds, the permit_id for permits, and the facility_id for tours). Inside a campground response, each site has its own campsite_id (the URL-segment for /camping/campsites/{id}) plus a legacy_id used by older Park-Service systems. The two are not interchangeable in URLs.
• HTML-escaped notice text. campsite.notices[].notice_text contains literal <p> / <strong> — un-escape before surfacing or you'll show raw entities.
• Rate-limiting is not enforced today but the agency reserves the right at launch moments. The Half Dome / Mt. Whitney / Wave lottery-window opening (15th of each month at 07:00 PT for Yosemite Valley campgrounds, mid-Feb for Mt. Whitney, etc.) historically triggers Akamai 503s and a CAPTCHA wall on /api/*. For real-time monitoring during a hot launch, switch to a Browserbase session with --advanced-stealth --proxies and back off on 429/503.
• state_code in suggest results is the full state name. /api/search/suggest returns state_code: "California", but /api/camps/campgrounds/{id} and /api/search return state: "CA". Don't equality-match across the two responses without normalizing.
• Sites in a campground have heterogeneous reserve types. campsite_reserve_type can be "Site-Specific" (book exact site), "Non Site-Specific" (book a site class, get one assigned at check-in), or "Group" / "Walk-Up Only". Surfaces in both the per-month and the per-site responses.
• READ-ONLY. Never POST to /api/reservations/*, /api/order/*, /api/permits/{id}/registration/*, or /api/timedentry/orders/*. Never click Reserve, Add to Cart, Add to Lottery, Apply, Proceed to Payment if you fall back to the browser.

Expected Output

Three distinct outcome shapes — campground, permit, tour.

// Campground — per-site, per-day matrix
{
  "kind": "campground",
  "facility_id": "232447",
  "facility_name": "Upper Pines Campground",
  "parent_recarea": "Yosemite National Park",
  "state": "CA",
  "facility_url": "https://www.recreation.gov/camping/campgrounds/232447",
  "checkin": "2026-06-15",
  "checkout": "2026-06-19",
  "filters_applied": {"site_type": "TENT ONLY", "group_size": 4, "pets_allowed": true},
  "sites_total": 235,
  "sites_after_filter": 71,
  "sites": [
    {
      "campsite_id": "98",
      "site_number": "040",
      "loop": "Upper Pines",
      "campsite_type": "RV NONELECTRIC",
      "reserve_type": "Site-Specific",
      "max_num_people": 6,
      "max_num_vehicles": 2,
      "is_accessible": false,
      "pets_allowed": "Domestic",
      "permitted_equipment": [
        {"equipment_name": "RV", "max_length_ft": 20},
        {"equipment_name": "Pop up", "max_length_ft": 18}
      ],
      "lat": 37.73751, "lon": -119.56544,
      "availability": {
        "2026-06-15": "Available",
        "2026-06-16": "Available",
        "2026-06-17": "Reserved",
        "2026-06-18": "Available"
      },
      "nightly_price_usd": null,
      "fees_breakdown": [{"label": "Peak", "amount_usd": 36.00}],
      "site_url": "https://www.recreation.gov/camping/campsites/98"
    }
  ]
}

// Permit / lottery — per-division, per-day quota
{
  "kind": "permit",
  "permit_id": "234652",
  "permit_name": "Half Dome Permits",
  "has_lottery": true,
  "lottery_state": {
    "active_lottery_id": "0d1b1413-57c2-4701-acf1-f0b227f7e58e",
    "is_active": true,
    "executed": false,
    "draw_at": "2026-03-15T00:00:00Z",
    "applications_close_at": "2026-03-01T23:59:59Z"
  },
  "divisions": [
    {
      "division_id": "31",
      "division_name": "Half Dome Cables (Daily)",
      "type": "Entry Point",
      "is_accessible": false,
      "is_lottery_option": false,
      "per_date": [
        {"date": "2026-06-01", "total_quota": 275, "remaining": 81, "show_walkup": false, "is_secret_quota": false},
        {"date": "2026-06-02", "total_quota": 275, "remaining": 62, "show_walkup": false, "is_secret_quota": false}
      ]
    }
  ],
  "permit_url": "https://www.recreation.gov/permits/234652"
}

// Tour / timed-entry — per-slot for one date
{
  "kind": "timedentry_tour",
  "facility_id": "10112471",
  "facility_name": "Mariposa Grove Commercial Bus Parking",
  "date": "2026-06-01",
  "booking_window": {
    "primary_opens_at":  "2026-05-02T08:00:00-07:00",
    "primary_closes_at": "2026-06-01T08:00:00-07:00"
  },
  "slots": [
    {
      "tour_time": "08:00",
      "inventory_total": 1,
      "available": 0,
      "reservation_count": 1,
      "is_secondary_window_only": false
    }
  ],
  "facility_url": "https://www.recreation.gov/ticket/facility/10112471"
}