Sunbeam & Boat Box Hot Springs - Free soaking · donation encouraged in Stanley, ID (2026)
A claw-foot tub and a few rock-walled pools borrow piping-hot water from the Sunbeam geothermal vents above the Salmon River. Locals ladle it into the tub and temper the soak with river water for quick roadside dips.
Sunbeam Hot Springs is one of the iconic free roadside soaks along the Sawtooth-corridor section of Idaho Highway 75 between Stanley and Challis — multiple primitive pools where 130°F vent water meets the Salmon River, including the famous Boat Box (a single round metal stock-tank perched on the riverbank). Bathers temper the vent water with cold Salmon River flow using ladles or rocks. Free, no permits, no facilities, run informally by Idaho Transportation Department maintenance. Best in summer through early fall when river flows are moderate; spring runoff floods the lower pools.
What to expect
Drive Highway 75 east of Stanley toward Challis. Multiple pull-outs along the river marked informally with worn paths down to the soaks. Boat Box is the most famous — a round metal tub perched at the riverbank, fed by a hot pipe that you can divert in or out. Other pool configurations change seasonally. Bring a wooden paddle (or use ones left by other soakers) to avoid grabbing the 140°F metal pipes. No facilities. Pack out everything.
Temperature
100°-105°F
Pools
3 soaking pools
Best season
May-October
Reservations
Walk-up friendly
Dog policy
Leashed dogs welcome
Family policy
Adults only
Safety notes
- Spring runoff swamps the tub and can sweep bathers downstream—stay out when the Salmon River is flood stage.
- Metal valves and pipes hit 140°F; use the provided wooden paddles when directing flow.
Amenities & etiquette
FAQ
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Nearby hot springs
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Goldbug Hot Springs
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A two-mile climb up BLM Trail #642 leads to cliffside tubs with sweeping views of the Salmon River Mountains. Backpackers spread out across primitive campsites tucked between the cascades and the main overlook pool.
Jerry Johnson Hot Springs
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Kirkham Hot Springs
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Dozens of thermal cascades pour over travertine ledges into the South Fork of the Payette River, creating adjustable rock tubs within a five-minute walk of the campground. Picnic tables and vault toilets make it one of Idaho's most accessible roadside springs.
Editor’s picks nearby
- Jerry Johnson Hot Springs — the iconic three-pool wild soak on US-12, 1.5-mile hike across the Lochsa swinging bridge — closed Dec 1–May 1 for elk winter range.
- Kirkham Hot Springs — the drive-up Highway 21 favorite along the South Fork Payette — multiple terraced pools.
- Goldbug Hot Springs — the Salmon River corridor classic — 2-mile uphill hike to terraced creekside pools above US-93.