Sunflower Hot Springs is a geothermal mineral spring in Idaho’s Boise National Forest along the Middle Fork of the Salmon River at 4,357 feet elevation. Long before fur trappers, miners, and homesteaders arrived, the Shoshone and Nez Perce used this part of central Idaho. Hot water emerges from bedrock about 30 feet above the river at 149°F, feeding five rock pools and spilling over stone to form a primitive natural shower where some flow cools to about 102°. The water contains calcium, potassium, magnesium, and sulfate, with a pH of 8.7. The site is valued for its very hot source, cooler soaking pools, and remote canyon setting.