# Grandjean Hot Spring, Idaho

Grandjean Hot Spring in Idaho. Hot. Roadside · Public Land. Boise County.

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

## Can you soak at Grandjean Hot Spring?

USGS lists Grandjean Hot Spring as a hot spring, with no temperature on record. You can drive right up to it. It's on US Forest Service land. We haven't confirmed whether it has a pool or charges a fee.

## Key facts

| Fact | Value |
|---|---|
| Source water temperature | Hot (USGS record; developed pools are often cooled) |
| Elevation | 5,000 ft |
| Access | Roadside · Public Land, 58 ft from the nearest road |
| Land | Boise National Forest, US Forest Service |
| County | Boise County |
| Nearest town | Idaho City |
| Coordinates | 44.16000, -115.16700 |
| Nearest campground | BONNEVILLE, 7.2 mi |

## About Grandjean Hot Spring

You can pull up to Grandjean Hot Spring without walking anywhere. It sits in Boise County, forty miles out of Idaho City. The ground belongs to the Boise National Forest and the public may use it. Listed as hot, with no temperature attached, so there is no degree reading to give here. Nobody sampled the water either. A photo exists, and a USGS site number. Not much else.

Under sixty feet from an unnamed road at five thousand feet. Snow is the big number here, better than fifteen feet a winter, and the year is moderately wet. Bonneville campground is around seven miles away and is the only camping the record lists. Nothing says what the pull-off or the spring looks like.

no season is on record. Temperature is unknown, so no soaking promise. It is a drive-up when the road is open, and with that snowfall the road is the thing to ask about. Bonneville campground for the night. Forest Service land, and the record marks access open.

## Nearby

- Nearest city page: [Hot springs near Challis](https://www.soakingsprings.com/hot-springs/near/idaho/challis), 19 mi away
- State page: [Hot springs in Idaho](https://www.soakingsprings.com/hot-springs/idaho)
- [Sacajawea Hot Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/sacajawea-hot-springs): 153°F source, Roadside, near Idaho City, Boise County, primitive pools, free, jul–oct
- [Bonneville Hot Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/bonneville-hot-springs): 185°F source, pH 9.3, Short Walk, near Idaho City, Boise County, primitive pools, pools 104°F, $5 parking or permit, apr–oct
- [Stanley Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/stanley-hot-spring): 106°F source, pH 8.8, Roadside, near Challis, Custer County
- [Elkhorn Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/elkhorn-hot-spring): 136°F source, Roadside, near Challis, Custer County, primitive pools, free, year-round
- [Rosalys Warm Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/rosalys-warm-spring): 106°F source, pH 9.4, Short Walk, near Sun Valley, Blaine County
- [Cape Horn Warm Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/cape-horn-warm-springs): 95°F source, pH 9.6, Short Walk, near Idaho City, Boise County

## Questions

**What is the water temperature at Grandjean Hot Spring?**
Grandjean Hot Spring is classified as hot. An exact temperature measurement has not been recorded.

**Where is Grandjean Hot Spring located?**
Grandjean Hot Spring is located in Boise County, Idaho at 5,000 feet elevation, near Idaho City. Coordinates: 44.1600°N, 115.1670°W.

**How do I get to Grandjean Hot Spring?**
Grandjean Hot Spring has Roadside road access (58 ft from the road).

**Is Grandjean Hot Spring free to visit?**
Grandjean Hot Spring has Open access. It is managed by US Forest Service.

**Can I camp near Grandjean Hot Spring?**
Yes, Bonneville is located nearby (7.2 miles away).

## Sources

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