An independent almanac of America's National Park Service sites.

What we are

National Sites Guide is an independent project that turns official National Park Service data into plain-English guides to when, where, and how to visit. We are not the NPS. We have no official affiliation with the agency or its concessioners. The goal is a single place where a visitor can answer "when should I go?" with numbers instead of vibes.

Our editorial standard

Every visitor-facing claim on this site must be either (1) derivable from data in our own pipeline, (2) verifiable on the official NPS page for that unit, or (3) widely cited across multiple authoritative sources with no contradiction. Specific times, dates, fees, distances, and wildlife-behavior windows are sourced or hedged. When in doubt we soften or remove the claim rather than ship something we can't back. A wrong page is worse than a terse one.

Inline citations follow a 3-tier rule: if a number is likely to change next year, or if acting on it costs money or risks safety, we link the source. If the source adds credibility but the visitor doesn't need to click, we name it. If the claim is an output of our own data pipeline or general seasonal knowledge confirmed across many sources, we leave it uncited and document the methodology separately.

The data pipeline

Our editorial pages rest on four official datasets, refreshed against the publishers below:

• NPS Visitor Use Statistics (2025 data package). Monthly recreation-visit counts for every NPS-administered unit, 1979 to current. Source: NPS IRMA Stats portal and the NPS DataStore record.
• NOAA NCEI U.S. Climate Normals, 1991-2020. Per-station monthly temperature, precipitation, and snowfall normals. Source: NOAA NCEI U.S. Climate Normals.
• NPS Data API. Unit names, designations, hours, alerts, and images. Source: developer.nps.gov. We use NPS-published photographs under 17 U.S.C. § 105, which places works produced by U.S. federal employees as part of their official duties in the public domain, subject to any image-specific notices the NPS attaches.
• NPS road and seasonal-operations pages. Per-unit road open/close windows, lodging seasons, and timed-entry rules — read from each park's official nps.gov/{unit}/planyourvisit/ pages and their authorized concessioners.

Sources we cite

Where a page makes a specific, falsifiable, or money-on-the-line claim, we link to the issuing authority. The recurring sources across the site are:

• National Park Service — per-unit pages for fees, hours, road status, safety, wildlife behavior, and reservations.
• NOAA / NCEI — official climate normals and current weather context.
• Recreation.gov — federal timed-entry, lottery, and campground reservations.
• AirNow — official EPA/NOAA/NPS air-quality reporting (wildfire smoke).
• USGS — elevation, hydrology, geology, and natural-hazard data.
• U.S. Naval Observatory — sunrise, sunset, and twilight tables for photographer-facing sections.
• NPS-authorized concessioners — operator-published lodging windows and rates, including Aramark / Yosemite Hospitality (travelyosemite.com), Xanterra / Yellowstone National Park Lodges (yellowstonenationalparklodges.com), and Delaware North / Grand Canyon Lodges (grandcanyonlodges.com).
• NPS cooperating associations — non-profit partners (Yellowstone Forever, Yosemite Conservancy, Grand Canyon Conservancy, and others) for visitor education materials.

Editorial team

Pages are produced by the National Sites Guide editorial team using a documented research-first authoring discipline: build a citation table before composing prose, then write only from the citation table, then run a fact-check pass before publishing. We do not run sponsored placements, affiliate links, or pay-to-feature listings in editorial copy.