Big Eightmile Creek Warm Spring
At 91 degrees Fahrenheit and 7,248 feet elevation, Big Eightmile Creek Warm Spring delivers a lukewarm soak in some of Idaho's most remote high country. Located in the Salmon National Forest of Lemhi County, it requires a short walk from Forest Road 096 through the kind of terrain most visitors only see from a distance.
The spring emerges in the upper reaches of the Eightmile Creek drainage, surrounded by the steep, dry ridges of the Lemhi Range. At this elevation, the air averages just 36 degrees Fahrenheit annually, and winter dumps nearly six feet of snow. The landscape is open sagebrush and scattered conifers, with the creek cutting through rocky ground. The 91-degree water feels warmer than it sounds when ambient temperatures hover near freezing.
The spring sits along one of many thermal corridors that thread through eastern Idaho's Basin and Range geology. Faults running parallel to the Lemhi Range allow groundwater to circulate deep enough to pick up modest heat before surfacing. The area around Salmon has been used by Shoshone-Bannock people for centuries, and early trappers and miners noted these warm seeps while working the surrounding drainages.
Access requires a roughly one-mile walk from Forest Road 096. The nearest established campground is McFarland, about 19 miles away along the Lemhi River, with nine reservable sites. Expect snow to block access from late fall through early summer. Bring everything you need, as there are no facilities at the spring itself.
Is Big Eightmile Creek Warm Spring worth visiting?
Best for
- Warm-water soaking
- Overnight camping trips
Overview McFarland Campground offer 9 campsites for both RVs and tent camping along the Lemhi River. The Lemhi Valley lies between the Beaverhead Mountains and the Lemhi Range, where the river creates a riparian zone in an otherwise arid region. Recreation McFarland Campground offers many recreation opportunities including public river access for fishing the Lemhi River, and area roads lead into the Beaverhead and Lemhi Ranges. The surrounding area offers a multitude of recreation opportunit...