# Sullivan Hot Springs, Idaho

Sullivan Hot Springs in Idaho. 106°F (41°C). Roadside. Custer County.

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

## Can you soak at Sullivan Hot Springs?

The water leaves the ground at 106°F, a comfortable soaking temperature. You can drive right up to it. We haven't confirmed whether it has a pool or charges a fee.

## Key facts

| Fact | Value |
|---|---|
| Source water temperature | 106°F (41°C) (USGS record; developed pools are often cooled) |
| pH | 6.9 (Neutral) |
| Total dissolved solids | 684 mg/L |
| Elevation | 5,540 ft |
| Access | Roadside, 112 ft from the nearest road |
| County | Custer County |
| Nearest town | Challis |
| Coordinates | 44.25400, -114.44300 |
| Best months to soak | December, January, February (largest gap between water and average air temperature) |
| Nearest campground | Pole Flat Campground, 14.1 mi |

## About Sullivan Hot Springs

A roadside soak outside Challis in Custer County, Sullivan Hot Springs runs a bit above a hundred degrees. Land owner and access status are blank in the record, which matters because a roadside spring with no ownership on file could be private. The water is notably mineral-heavy, with iron on the list.

Dry side of the state, under twenty inches of precipitation, with around ninety inches of snow in a normal winter and an annual average temperature in the low forties. Elevation is about 5,500 feet. A hundred-odd feet separate the water from the road, so walking is not a factor. Who owns the land is not recorded, and no road is named.

The record's best months run December through February. Pole Flat Campground, about fourteen miles off, is the closest camping. The reading dates to November 1983, a USGS sample. Water in the low hundreds is comfortable for most people, but check ownership before going; nothing in the record says this is public.

## Water chemistry

Lab sample from 1983-11-02 (Water Quality Portal).

| Measure | Value |
|---|---|
| pH | 6.9 |
| Total dissolved solids | 684 mg/L |
| Calcium | 48 mg/L |
| Magnesium | 11 mg/L |
| Sodium | 170 mg/L |
| Sulfate | 39 mg/L |
| Chloride | 57 mg/L |
| Iron | 50 µg/L |

## 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)
- [Slate Creek Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/slate-creek-hot-spring): 122°F source, pH 8.8, TDS 352 mg/L, Short Walk, near Challis, Custer County, primitive pools, free, jul-oct best
- [Robinson Bar Hot Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/robinson-bar-hot-springs): 131°F source, pH 9.4, TDS 294 mg/L, Roadside, near Challis, Custer County
- [Sunbeam Hot Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/sunbeam-hot-springs): 169°F source, pH 9.0, TDS 291 mg/L, Roadside, near Challis, Custer County, primitive pools, pools 100–110°F, free, year-round
- [Basin Creek Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/basin-creek-hot-spring): 133°F source, pH 9.5, Roadside, near Challis, Custer County, primitive pools, jun–oct
- [West Pass Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/west-pass-hot-spring): 124°F source, pH 8.5, Roadside, near Sun Valley, Blaine County
- [Lower Bowery Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/lower-bowery-hot-spring): 129°F source, pH 8.5, Short Walk, near Sun Valley, Blaine County, primitive pools, may–dec

## Questions

**What is the water temperature at Sullivan Hot Springs?**
Sullivan Hot Springs has a water temperature of 106°F (41°C). This is considered a hot spring, well above body temperature.

**Where is Sullivan Hot Springs located?**
Sullivan Hot Springs is located in Custer County, Idaho at 5,540 feet elevation, near Challis. Coordinates: 44.2540°N, 114.4430°W.

**How do I get to Sullivan Hot Springs?**
Sullivan Hot Springs has Roadside road access (112 ft from the road).

**Can I camp near Sullivan Hot Springs?**
Yes, Pole Flat Campground is located nearby (14.1 miles away).

**What minerals are in the water at Sullivan Hot Springs?**
Water chemistry analysis shows the presence of pH, Total Dissolved Solids, Calcium, Magnesium, Sodium, Sulfate, Chloride, Iron. The pH is 6.9 (neutral). Total dissolved solids measure 684 mg/L.

## Sources

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