Forge Creek Hot Springs
Forge Creek Hot Springs requires a committed 3.6-mile hike from the nearest road to reach its source at 5,920 feet in the Salmon National Forest. The USGS measured the water at 97 degrees F with a pH of 8.7, and the remote location in Custer County near Challis ensures few visitors make the journey to this genuine backcountry thermal feature.
The trail follows Forge Creek through dense conifer forest typical of central Idaho's mountain drainages. The creek provides a constant soundtrack as the path climbs through Douglas fir and spruce. At the springs, the warm water seeps into the creek channel, creating pockets of mixed-temperature water along the streambed. The surrounding forest is thick enough to block most wind, creating a sheltered feel. Annual snowfall averages over 8 feet, and the trail is typically snow-free only from July through September. Wildlife sign is common in this lightly traveled drainage.
The Salmon National Forest encompasses some of Idaho's most geologically active terrain, where deep faults in the Idaho Batholith channel heated groundwater to the surface. Forge Creek's chemistry, with 67 mg/L sodium and low calcium, follows the pattern of deep-circulating batholith springs. The alkaline pH of 8.7 indicates prolonged contact with granitic rock at depth. The remote character of this drainage has remained largely unchanged since Forest Service administration began in the early 1900s.
This is a backcountry destination requiring a 3.6-mile hike each way. Carry a topographic map and be prepared for route-finding in spots. Yellowjacket Guard Station, a historic 1925 Forest Service cabin about 8 miles away, is reservable for overnight stays. Snow limits access to a short summer window, roughly mid-July through September. Creek crossings may be required. Pack out all trash and practice Leave No Trace principles.
Is Forge Creek Hot Springs worth visiting?
Best for
- Overnight camping trips
The water at Forge Creek Hot Springs is alkaline (pH 8.7).
Overview Yellowjacket Guard Station is a historic Forest Service Ranger Station and Work Center. Originally constructed in 1925 and remodeled in 1934 by the Civilian Conservation Corps, the structure is eligible for listing on the National Register of Historic Places. Recreation Hikers, horseback riders, mountain bikers and off-road enthusiasts will find many trails in the surrounding area. Hunting is also a popular activity. Click here for an Idaho OHV safety messageFacilities The spacious...