Sources and licences

• OpenStreetMap (ODbL): locations, names, fee and facility tags, temperature where mapped.
• Wikidata (CC0): extra springs, official website links and Commons photo links.
• US Forest Service Recreation Opportunities database and Recreation.gov RIDB export (US federal works, public domain): official status, fee, season and description fields.
• NOAA NCEI Thermal Springs List for the United States (Berry, Grim & Ikelman 1980, doi:10.25921/c8p0-zs06): used only to confirm a spring is at a known thermal location. Not updated since 1980; we don't show its temperatures.
• Official pages: short verbatim quotes with URL and the date read.
• Photos: Wikimedia Commons, CC0 / public domain / CC BY / CC BY-SA only, author and licence shown with each photo.
• Boundaries: Natural Earth (public domain), US Census state outlines (public domain).
• Base map: OpenFreeMap © OpenMapTiles, data from OpenStreetMap. MapLibre GL JS (BSD-3-Clause), served from this site.

OpenStreetMap

Map data © OpenStreetMap contributors, available under the Open Database License (ODbL). These pages are a produced work from that data. If we publish the underlying OSM-derived database, we will release it under the ODbL. Official-page checks are kept as a separate dataset.

How we check details

We read the official page (the operator, the land agency or the park) and store short verbatim quotes of what it says about fees, seasons, clothing policy, reservations and rules, together with the URL and the date we read it. We show quotes rather than our own conclusions, and we never say a spring is safe. If a page is ambiguous we record nothing.

What we leave out

Features that are not for bathing (geysers, fumaroles, mud pots), springs inside parks that prohibit soaking, points marked private or no-access in OpenStreetMap, unnamed points, and points whose names show they were mis-tagged. The full removal log ships with the dataset.