Basin Creek Hot Spring
Basin Creek Hot Spring surfaces at 133 degrees Fahrenheit directly along the Salmon River Scenic Byway in Custer County, just three meters from the pavement. At 6,060 feet elevation in the Challis National Forest, it combines serious geothermal heat with drive-up convenience, a rare pairing among Idaho's backcountry-oriented thermal features.
The spring steams beside the byway where Basin Creek meets the Salmon River corridor. Lodgepole pine and Douglas fir climb the slopes above, while willows and alder line the creek bottom. The Salmon River itself flows nearby, cold and clear, offering a stark temperature contrast. Annual snowfall exceeds 10 feet, and the surrounding peaks hold snow into July. The highly alkaline water, with a pH of 9.5 and dominant sodium chemistry, leaves a slick mineral film on the rocks around the source.
Custer County sits at the heart of Idaho's thermal belt, where the Idaho Batholith's deep granitic rock stores and transmits geothermal energy along an extensive network of faults. Basin Creek Hot Spring's sodium-sulfate chemistry with minimal calcium indicates deep circulation through granite, dissolving silica and alkali minerals at temperatures well above what reaches the surface. The Salmon River Scenic Byway follows a route used by indigenous peoples and later by Lewis and Clark's expedition.
The spring sits virtually roadside on the Salmon River Scenic Byway, making it one of the easiest hot springs to reach in central Idaho. Water at 133 degrees Fahrenheit will burn skin, so do not enter the source. Pole Flat Campground lies 9 miles away with vault toilets and drinking water, first-come first-served. The byway is paved and generally accessible May through October. Winter travel requires checking road conditions with the Challis Ranger District.
Is Basin Creek Hot Spring worth visiting?
Best for
- Hot spring soaking
- Easy day trips
- Overnight camping trips
The water at Basin Creek Hot Spring is alkaline (pH 9.5).
Some links are affiliate links. We may earn a commission at no extra cost to you.
This campground is away from the main road and up the hill overlooking the river and the dredge ponds. Campsites include picnic tables tent pads fire rings with cooking grills. Campground amenities include a vault toilet and drinking water. Sites accommodate trailers and motorhomes up to 32 feet long.