About Soaking Springs
A free guide to America's hot springs, built from public data
What This Site Is
Soaking Springs is a free guide to the natural hot springs of the United States. Each spring has its own page with a water temperature, lab chemistry where someone has tested it, directions and the campgrounds nearby. You don't need an account to read any of it.
Most visitors show up while planning a trip. If you'd rather know why the water comes out hot at all, start with the geothermal map or the mineral guides.
Where the Data Comes From
Every page starts from public records. Here's where each piece comes from:
- USGS: The U.S. Geological Survey's thermal spring records give each spring its location and measured temperature.
- Water Quality Portal: Lab results for pH, dissolved solids and individual minerals come from this federal database, which the USGS and EPA run together.
- National Weather Service: Current conditions and forecasts on spring and city pages are pulled from weather.gov every couple of hours.
- OpenStreetMap: Roads and trails mapped by volunteers help describe how to reach a spring.
- Wikipedia & Wikidata: Background and references for the better known springs.
- Recreation.gov: Fees and reservation details for campgrounds on public land.
- Stanford Thermal Earth Model: Estimates of how much heat rises through the ground under each spring (Aljubran & Horne, 2024, CC BY 4.0).
- USGS 3DEP & Landsat: Elevation data, mostly from lidar, draws the terrain views. Landsat's thermal band shows where the ground runs warm.
- Wikimedia Commons & Flickr: Photos shared under open licenses, credited under each one.
- SimpleMaps: City locations and populations for the nearby springs pages (CC BY 4.0).
Open Data
Public data should be easy to get to, so nothing here sits behind a paywall. Sources are credited on the pages that use them. If you find a missing credit or a number that looks off, the contact page goes straight to Armen.
What's Covered
The guide lists natural thermal springs in every state where one has been documented, from resort pools to small seeps a few miles up a trail. Plenty of the old USGS records are thin. Some pages have little beyond a location and a temperature, and they fill in as better data turns up.
About the Author
