Every fact on OutsideAtlas traces back to a public source. Here’s the full list — official agencies, open datasets, license terms, and refresh cadence.
Source: OpenStreetMap via the Overpass API.
License: Open Database License (ODbL) — © OpenStreetMap contributors.
Coverage: 0 named trails across 0 US states.
Refresh: Weekly.
What we use: name, geometry (centroid), length, elevation, surface, foot/bicycle/horse/dog access, SAC scale, trail visibility, operator, network, references.
Source: Recreation.gov via the Recreation Information Database (RIDB) API.
License: U.S. Government Work / public domain.
Coverage: 0 federal parks, recreation areas, facilities, and campgrounds. Individual campsites with hookups, capacity, and reservation links.
Refresh: Weekly.
RIDB is administered by the National Park Service, U.S. Forest Service, Bureau of Land Management, U.S. Fish & Wildlife Service, U.S. Army Corps of Engineers, Bureau of Reclamation, NOAA, Tennessee Valley Authority, Smithsonian, and the National Archives.
Source: Open-Meteo (forecast + air quality endpoints).
License: CC-BY 4.0 — attribution required (we link back on every weather block).
Refresh: Every 6 hours, server-side cached.
What we use: 5-day daily max/min temp, humidity, precipitation probability + total, wind, UV index, sunrise/sunset, weather code, US EPA AQI.
Counties: US Census TIGER cartographic boundary files — public domain. We use these as polygons for offline point-in-polygon county lookup.
Cities: Kelvins US Cities Database — ~29K incorporated places with state, county, and lat/lon. We use these as centroids for nearest-city lookup via kdbush spatial index.
License: Both datasets are open / public domain.
Source: OpenStreetMap tile servers rendered via the Leaflet JavaScript library.
License: Tiles served under the OSM Tile Usage Policy. We keep request volume reasonable and cache on the client.
For authoritative status (closures, permits, fees, current conditions), visit the agency managing the trail or park:
Aggregation, normalization, classification rules, and refresh cadences are documented on our Methodology page.