# Mormon Ranch Warm Spring, Idaho

Mormon Ranch Warm Spring in Idaho. Hot. Hike · Public Land. Custer County.

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

## Can you soak at Mormon Ranch Warm Spring?

USGS lists Mormon Ranch Warm Spring as a hot spring, with no temperature on record. 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 | Hot (USGS record; developed pools are often cooled) |
| pH | 9.4 (Alkaline) |
| Elevation | 4,300 ft |
| Access | Hike · Public Land, 3.0 mi from the nearest road |
| Land | Salmon National Forest, US Forest Service |
| County | Custer County |
| Nearest town | Challis |
| Coordinates | 44.95100, -114.70400 |
| Nearest campground | YELLOWJACKET GUARD STATION, 11.2 mi |

## About Mormon Ranch Warm Spring

Mormon Ranch Warm Spring is a Forest Service spring in Custer County, three miles by foot from the closest road and nearly forty miles from Challis. The name says warm and the survey note says hot, and no temperature was written down, so take the name lightly. The water, sampled decades ago, came back strongly alkaline. Salmon National Forest land, listed open to the public.

Mid-elevation mountain country, a bit over four thousand feet, with snowfall approaching eight feet in a typical winter and moderate precipitation. That much snow closes the approach for a long stretch of the year. The three-mile hike in is the defining fact of the place. No road name is on file. Nothing in the record describes the trail or the ground around the source.

No best months are listed, so go by the snow. Summer into early fall is the realistic window, and confirm with the forest before heading out. Overnight options on file come down to Yellowjacket Guard Station, some eleven miles distant. No fee appears in the record. Because the temperature is unrecorded, check the water carefully before getting near it. It might be a soak or it might be hotter than skin can take.

## Water chemistry

Lab sample from 1980-06-29 (Water Quality Portal).

| Measure | Value |
|---|---|
| pH | 9.4 |
| Calcium | 2.8 mg/L |
| Sodium | 50 mg/L |
| Sulfate | 29 mg/L |
| Chloride | 5.3 mg/L |

## Nearby

- Nearest city page: [Hot springs near Challis](https://www.soakingsprings.com/hot-springs/near/idaho/challis), 48 mi away
- State page: [Hot springs in Idaho](https://www.soakingsprings.com/hot-springs/idaho)
- [Snowshoe Johnsons Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/snowshoe-johnsons-hot-spring): 108°F source, Hike, near Challis, Custer County
- [Forge Creek Hot Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/forge-creek-hot-springs): Hot, pH 8.7, Hike, near Challis, Custer County
- [Hospital Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/hospital-hot-spring): 115°F source, pH 8.9, TDS 278 mg/L, Hike, near Challis, Custer County, primitive pools, parking or permit fee, late may-sep (river permit season)
- [Lower Loon Creek Hot Spring, ID](https://www.soakingsprings.com/hot-springs/idaho/lower-loon-creek-hot-spring): 120°F source, pH 9.0, Short Walk, near Challis, Custer County, primitive pools, parking or permit fee, late may-sep (river permit season)
- [Cox Hot Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/cox-hot-springs): 131°F source, pH 8.9, Hike, near Challis, Custer County
- [Foster Ranch Hot Springs, ID](https://www.soakingsprings.com/hot-springs/idaho/foster-ranch-hot-springs): 135°F source, pH 9.1, Hike, near Challis, Custer County

## Questions

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

**Where is Mormon Ranch Warm Spring located?**
Mormon Ranch Warm Spring is located in Custer County, Idaho at 4,300 feet elevation, near Challis. Coordinates: 44.9510°N, 114.7040°W.

**How do I get to Mormon Ranch Warm Spring?**
Mormon Ranch Warm Spring has Hike road access (3.0 mi from the road).

**Is Mormon Ranch Warm Spring free to visit?**
Mormon Ranch Warm Spring has Open access. It is managed by US Forest Service.

**Can I camp near Mormon Ranch Warm Spring?**
Yes, Yellowjacket Guard Station is located nearby (11.2 miles away).

**What minerals are in the water at Mormon Ranch Warm Spring?**
Water chemistry analysis shows the presence of pH, Calcium, Sodium, Sulfate, Chloride. The pH is 9.4 (alkaline).

## Sources

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