# Rattlesnake Hot Spring, Idaho

Rattlesnake Hot Spring in Idaho. 133°F (56°C). Hike · Public Land. Boise County.

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

## Can you soak at Rattlesnake Hot Spring?

Only once it cools. The water leaves the ground at 133°F, hotter than any hot tub. Reaching it takes a hike. 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 | 133°F (56°C) (USGS record; developed pools are often cooled) |
| Elevation | 4,216 ft |
| Access | Hike · Public Land, 1.1 mi from the nearest road |
| Land | Boise National Forest, US Forest Service |
| County | Boise County |
| Nearest town | Idaho City |
| Coordinates | 43.60500, -115.66400 |
| Best months to soak | December, January, February (largest gap between water and average air temperature) |
| Nearest campground | Big Roaring River Lake Campground, 11.1 mi |

## About Rattlesnake Hot Spring

Boise National Forest land holds Rattlesnake Hot Spring, in Boise County, 17 miles or so beyond Idaho City. The water is hot, near the upper end of what will cool to a soakable temperature. Access is open to anyone. No sample was ever taken and no USGS number assigned, which leaves the temperature as the one solid thing known about this water.

A hike of a bit over a mile in from a road the record leaves nameless. Forest Service land at moderate elevation. Snow totals are moderate too, around four and a half feet, and the year is fairly dry with a cool average.

Big Roaring River Lake Campground, eleven miles out, is the camp on file. Winter, per the record. The water is hot enough to hurt, so find a cooled spot before you sit. With no chemistry to go by, you are relying on your own senses. The walk in is a little over a mile, so this is a hike, short as it is.

## Nearby

- Nearest city page: [Hot springs near Boise](https://www.soakingsprings.com/hot-springs/near/idaho/boise), 16 mi away
- State page: [Hot springs in Idaho](https://www.soakingsprings.com/hot-springs/idaho)
- [Twin Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/twin-springs-1): 151°F source, pH 9.5, TDS 217 mg/L, Roadside, near Idaho City, Boise County, developed pools
- [Sheep Creek Bridge Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/sheep-creek-bridge-hot-spring): 142°F source, pH 9.5, Roadside, near Idaho City, Boise County, primitive pools, free
- [Smith Cabin Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/smith-cabin-hot-spring): 138°F source, pH 9.5, Roadside, near Idaho City, Boise County, primitive pools, free
- [Loftus Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/loftus-hot-spring): 129°F source, pH 9.6, Roadside, near Idaho City, Boise County, primitive pools, pools 100–110°F, free, year-round
- [Basset Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/basset-hot-spring): Hot, Hike, near Idaho City, Boise County
- [Vaughn Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/vaughn-hot-spring): 154°F source, Short Walk, near Idaho City, Boise County, primitive pools, jul–nov

## Questions

**What is the water temperature at Rattlesnake Hot Spring?**
Rattlesnake Hot Spring has a water temperature of 133°F (56°C). This is considered a hot spring, well above body temperature.

**Where is Rattlesnake Hot Spring located?**
Rattlesnake Hot Spring is located in Boise County, Idaho at 4,216 feet elevation, near Idaho City. Coordinates: 43.6050°N, 115.6640°W.

**How do I get to Rattlesnake Hot Spring?**
Rattlesnake Hot Spring has Hike road access (1.1 mi from the road).

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

**Can I camp near Rattlesnake Hot Spring?**
Yes, Big Roaring River Lake Campground is located nearby (11.1 miles away).

**Is it safe to soak at Rattlesnake Hot Spring?**
With care. At 133°F Rattlesnake Hot Spring is hot enough to need short sessions, fifteen to twenty minutes, and plenty of water. Enter slowly and get out if you feel light-headed.

## Sources

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