# Portneuf River Warm Spring, Idaho

Portneuf River Warm Spring in Idaho. 93°F (34°C). Short Walk. Caribou County.

- Page: https://www.soakingsprings.com/hot-springs/idaho/portneuf-river-warm-spring
- Source: Soaking Springs, researched and maintained by Armen Suny
- Updated: 2026-09-14

## Can you soak at Portneuf River Warm Spring?

The water leaves the ground at 93°F, a comfortable soaking temperature. It's a short walk from the road. We haven't confirmed whether it has a pool or charges a fee.

## Key facts

| Fact | Value |
|---|---|
| Source water temperature | 93°F (34°C) (USGS record; developed pools are often cooled) |
| pH | 6.2 (Slightly Acidic) |
| Elevation | 5,308 ft |
| Access | Short Walk, 0.1 mi from the nearest road (Kelly Toponce Road) |
| County | Caribou County |
| Nearest town | Soda Springs |
| Coordinates | 42.78100, -111.98300 |
| Best months to soak | December, January, February (largest gap between water and average air temperature) |
| Nearest campground | PEBBLE GUARD STATION, 5.5 mi |

## About Portneuf River Warm Spring

Portneuf River Warm Spring, in Caribou County, is about 22 miles from Soda Springs. Soaking warm is the category here, low nineties when measured in 1977, with a trickle of flow and slightly acidic water. Who holds the land is unknown, and so is your right to be there. OpenStreetMap has no second name for it.

Kelly Toponce Road is the approach, roughly five hundred feet away, which makes for a short walk. The country is high, averaging in the mid forties across the year, with close to six feet of snow each winter and modest precipitation otherwise.

Pebble Guard Station is the nearest camp on record, five or six miles off. Winter months are the ones the record recommends. Flow was measured at a tenth of a cubic foot per second, which is very little, so the volume of water is small. Land status is unknown; find out before you go. The reading is from 1977.

## Water chemistry

Lab sample from 1977-08-23 (Water Quality Portal).

| Measure | Value |
|---|---|
| pH | 6.2 |
| Calcium | 280 mg/L |
| Magnesium | 64 mg/L |
| Sodium | 81 mg/L |
| Sulfate | 270 mg/L |
| Chloride | 62 mg/L |

Records this spring holds:
- Most acidic of Idaho's 171 springs with a pH reading: pH 6.2

## Nearby

- Nearest city page: [Hot springs near Blackfoot](https://www.soakingsprings.com/hot-springs/near/idaho/blackfoot), 25 mi away
- State page: [Hot springs in Idaho](https://www.soakingsprings.com/hot-springs/idaho)
- [Lava Hot Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/lava-hot-springs): 113°F source, pH 6.8, TDS 776 mg/L, Roadside, near Soda Springs, Caribou County, developed pools, pools 102–112°F, $8 day pass, year-round
- [Lava Hot Springs (Thermal Mineral Springs), ID](https://www.soakingsprings.com/hot-springs/idaho/lava-hot-springs-thermal-mineral-springs): pH 6.8, TDS 776 mg/L, Roadside, near Soda Springs, Caribou County, developed pools, pools 102–112°F, $8 day pass, year-round
- [Alkali Flats Warm Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/alkali-flats-warm-spring): 93°F source, pH 6.6, Short Walk, near Shelley, Bingham County
- [Blackfoot River Warm Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/blackfoot-river-warm-spring): 79°F source, Roadside, near Soda Springs, Caribou County
- [Steamboat Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/steamboat-hot-spring): 88°F source, TDS 1,450 mg/L, Short Walk, near Soda Springs, Caribou County
- [Soda Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/soda-springs-2): 82°F source, Roadside, near Soda Springs, Caribou County

## Questions

**What is the water temperature at Portneuf River Warm Spring?**
Portneuf River Warm Spring has a water temperature of 93°F (34°C). This is a warm thermal spring.

**Where is Portneuf River Warm Spring located?**
Portneuf River Warm Spring is located in Caribou County, Idaho at 5,308 feet elevation, near Soda Springs. Coordinates: 42.7810°N, 111.9830°W.

**How do I get to Portneuf River Warm Spring?**
Portneuf River Warm Spring has Short Walk road access, with the nearest road being Kelly Toponce Road (0.1 mi from the road).

**Can I camp near Portneuf River Warm Spring?**
Yes, Pebble Guard Station is located nearby (5.5 miles away).

**What minerals are in the water at Portneuf River Warm Spring?**
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 6.2 (slightly acidic).

## Sources

- USGS thermal springs records, Water Quality Portal lab analyses, OpenStreetMap, Wikipedia/Wikidata, NOAA climate normals