Natural hot spring · Idaho
Portneuf River Warm Spring
Caribou County, Idaho · 21 miles northwest of Soda Springs, ID
Last updated
- Type
- Natural Natural hot spring
- Water temperature
- 93°F (34°C) at the source
- Cost
- Not recorded
- Hours or season
- Not recorded
- Clothing
- Not recorded
- Nearest town
- Soda Springs, ID (21 mi / 34 km)
- Coordinates
- Pools or sources
- 1
- Historical record only: this spring has not been confirmed on the ground since 1981 and may be on private land.
About Portneuf River Warm Spring
Portneuf River Warm Spring is a natural hot spring in Caribou County, Idaho, about 21 miles northwest of Soda Springs, ID. The nearest large city is Pocatello, ID, roughly 24 miles away as the crow flies.
The temperature at the source has been recorded at 93°F (34°C). That puts it in the "warm" range. Comfortable for long soaks, like a warm bath that has cooled a little.
It is a natural spring with little or no development. Some natural springs have rock pools you can sit in, while others are too hot, too shallow or on land where soaking is not allowed.
This spring comes from the US federal Thermal Springs List compiled in 1981. Nobody has confirmed it on the ground for this directory since, so treat the details as historical. Many springs on that list sit on private ranch land, so never visit without permission.
Water temperature
Warm. Comfortable for long soaks, like a warm bath that has cooled a little.
Readings come from the NOAA thermal springs list, and other public sources. Temperatures change with season, flow and pool design. See our soak temperature guide for safe soaking times.
Map and directions
Red marks Portneuf River Warm Spring. Other colored dots are nearby springs in this directory. Coordinates: 42.78100, -111.98300.
Getting there
- Nearest town: Soda Springs, ID. The spring is about 21 miles (34 km) northwest of town in a straight line.
- Nearest large city: Pocatello, ID, about 24 miles (39 km) in a straight line.
- Planning from a city? See hot springs near Pocatello, ID.
- Use the directions buttons above for a driving route. Final roads to many springs are unpaved, seasonal or closed in winter, so check road conditions before you go.
Weather forecast
Live forecast for this exact spot from the US National Weather Service.
Hot springs near Portneuf River Warm Spring
- Lava Hot Springs 113°F
- Alkali Flats Warm Spring 93°F
- Steamboat Hot Spring 88°F
- Wilson Lake Warm Spring 86°F
- Henry Warm Spring 86°F
- Downata Hot Springs 109°F
Before you go
- Check the operator, land manager or park website for current hours, fees and closures. Details in any directory can go out of date.
- Pack out everything you bring, including food scraps. Do not use soap in natural pools.
- Keep your head above water. Warm fresh water can carry Naegleria fowleri, a rare but deadly amoeba that enters through the nose.
- Drink water, limit soaks to 10 to 20 minutes at a time in very hot water, and skip alcohol.
- Read our hot spring etiquette guide and safety guide.
Frequently asked questions
How hot is Portneuf River Warm Spring?
The temperature at the source has been recorded at 93°F (34°C), which is warm. Comfortable for long soaks, like a warm bath that has cooled a little.
Where is Portneuf River Warm Spring?
Portneuf River Warm Spring is in Caribou County, Idaho, about 21 miles northwest of Soda Springs, ID. The GPS coordinates are 42.7810, -111.9830.
Can you soak at Portneuf River Warm Spring?
Natural springs vary. Some have pools built by visitors, others are too hot or shallow, and some are on private land or in areas where bathing is banned. Check local rules and test the water before you get in.
What hot springs are near Portneuf River Warm Spring?
The closest listed spring is Lava Hot Springs, about 11 miles south. Alkali Flats Warm Spring is about 18 miles away.
What should I bring to a hot spring?
Water to drink, a towel, sandals with grip, a bag to pack out trash, and warm layers for after your soak. At primitive springs bring a headlamp and tell someone where you are going.
Sources and corrections
This listing combines the NOAA NCEI Thermal Springs List. Data last refreshed August 2026. Source 1
Visited recently? Send a correction, such as a temperature reading, fee, closure or photo. If you look after this spring and want it removed, see removal requests.