Idaho has more soakable natural hot springs than any other state in the US, with roughly 130 of its 340 known geothermal springs accessible for bathing across the central mountains and river corridors, from developed resort pools to free roadside and backcountry springs like Mile 16 Hot Springs near Cascade and Loftus Natural Hot Spring on the Middle Fork Boise River southeast of Boise. Water temperatures at hot springs in Idaho typically range from 100 to 110 degrees at undeveloped sources, with cooler pools forming where geothermal water mixes with river flow and developed facilities holding their pools between 102 and 106 degrees year-round. Each listing below includes access details, water conditions and notes on facilities so you can plan your visit with current information.
