# Twin Springs, Idaho

Twin Springs in Idaho. 151°F (66°C). Roadside · Public Land. Boise County.

- Page: https://www.soakingsprings.com/hot-springs/idaho/twin-springs-1
- Source: Soaking Springs, researched and maintained by Armen Suny
- Updated: 2026-09-14

## Can you soak at Twin Springs?

Yes. Twin Springs is a developed hot spring.

## Key facts

| Fact | Value |
|---|---|
| Source water temperature | 151°F (66°C) (USGS record; developed pools are often cooled) |
| pH | 9.5 (Alkaline) |
| Total dissolved solids | 217 mg/L |
| Elevation | 3,440 ft |
| Access | Roadside · Public Land, 9 ft from the nearest road (North Fork Boise River Road) |
| Land | Boise National Forest, US Forest Service |
| County | Boise County |
| Nearest town | Idaho City |
| Coordinates | 43.67100, -115.69600 |
| Best months to soak | December, January, February (largest gap between water and average air temperature) |
| Nearest campground | Ninemeyer Campground, 8.6 mi |

## Plan your visit

| | |
|---|---|
| Type | Developed pools |
| Cost | Cabins $160 per night riverfront (2 adults), 2 night minimum; day use tub fee not published |
| Getting there | Rough road along Middle Fork Boise River, no cell service |
| In winter | Rough road, high clearance recommended |
| Operator | Twin Springs Resort, https://twinspringsidaho.com |

Checked October 2026. Sources: https://twinspringsidaho.com/faq, https://hotspringslocator.com/twin-springs-resort, https://idahohotsprings.com/destinations/twin-springs-resort/index.htm

## Soaking safety

**Very Hot Source, Use Extreme Caution.** At 151°F, the source water at Twin Springs is hot enough to cause burns. Some hot springs this hot have cooler side pools or downstream areas suitable for soaking. Always test the water temperature before entering.

## About Twin Springs

Twin Springs is a scalding source on North Fork Boise River Road in Boise National Forest, about thirteen miles from Idaho City. The water comes out hot enough to burn skin on contact, so this is a thermal feature to look at, and to enter only in spots where the heat has drained out of it. Access is listed as open. Low dissolved solids and a high pH characterize the sample on file.

The road passes essentially on top of the spring, nine feet away by the measurement on file, and the walk is a matter of a few steps. This is Forest Service land at around thirty-four hundred feet. Snowfall is moderate, about seventy-five inches, in a fairly dry climate.

The record's pick for timing is the dead of winter. Ninemeyer Campground is about nine miles off. Since the spring sits on the road shoulder, no walking is involved. The water leaves the ground scalding. Do not step in anywhere you have not tested, and keep children and dogs back from the outflow. The figures come from a May 1981 survey.

## Water chemistry

Lab sample from 1981-05-27 (Water Quality Portal).

| Measure | Value |
|---|---|
| pH | 9.5 |
| Total dissolved solids | 217 mg/L |
| Calcium | 1.7 mg/L |
| Magnesium | 0.1 mg/L |
| Sodium | 49 mg/L |
| Sulfate | 21 mg/L |
| Chloride | 1.6 mg/L |
| Iron | 20 µg/L |

## 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)
- [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
- [Rattlesnake Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/rattlesnake-hot-spring): 133°F source, Hike, near Idaho City, Boise County
- [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
- [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
- [Basset Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/basset-hot-spring): Hot, Hike, near Idaho City, Boise County

## Questions

**What is the water temperature at Twin Springs?**
Twin Springs has a water temperature of 151°F (66°C). This is considered a hot spring, well above body temperature.

**Where is Twin Springs located?**
Twin Springs is located in Boise County, Idaho at 3,440 feet elevation, near Idaho City. Coordinates: 43.6710°N, 115.6960°W.

**How do I get to Twin Springs?**
Twin Springs has Roadside road access, with the nearest road being North Fork Boise River Road (9 ft from the road).

**Is Twin Springs free to visit?**
Twin Springs has Open access. It is managed by US Forest Service.

**Can I camp near Twin Springs?**
Yes, Ninemeyer Campground is located nearby (8.6 miles away).

**What minerals are in the water at Twin Springs?**
Water chemistry analysis shows the presence of pH, Total Dissolved Solids, Calcium, Magnesium, Sodium, Sulfate, Chloride, Iron. The pH is 9.5 (alkaline). Total dissolved solids measure 217 mg/L.

**Is it safe to soak at Twin Springs?**
No, not at the source. The water at Twin Springs reaches 151°F, which can cause severe burns within seconds. Look for cooled side pools or downstream stretches, and test with a hand before anything else.

## Sources

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