Roystone Hot Springs

Roystone Hot Springs is a primitive geothermal site in Custer County, Idaho, north of Challis and near the headwaters of tributaries of the Salmon River. The spring emerges at around 46°C from a hillside and flows into a small rock soaking pool. The access road requires a high-clearance vehicle, and the surrounding high desert landscape of sagebrush flats and volcanic rock formations makes the approach as interesting as the destination. The springs see limited use, giving them a genuinely wild character.