Boat Box Hot Springs, also known as Elkhorn Hot Springs, is a unique, roadside geothermal soak just minutes from Stanley, Idaho. It is a primitive but scenic soaking spot conveniently located near Highway 75 within the Sawtooth National Recreation Area.

Its quirky metal tub, riverside setting, and easy access make it a must-visit gem when traveling along the Salmon River.

The name of the spring comes from the old, rounded wooden soaking box used as a tub here before. Unfortunately, the rapid currents of the Salmon River swept the box away, and a metal tub was installed in its stead. The new tub was also secured with metal cables so that it would not repeat the fate of its predecessor.

Salmon River rafters often use the Boat Box Hot Spring as a rest spot.

Boat Box Hot Springs Geothermal Experience

The hot geothermal mineral water flows out of the source at 138°F (59°C). A pipe under the highway directs it into a caldron-shaped metal tub. The water directly from the source is too hot to soak in without cooling it down first. To do so, divert the pipe from the tub and use a bucket available on site to add cool water from the river.

There are also volunteer-built primitive rock-and-sand pools right next to the tub. You can also enjoy a comfortable soak there at a much lower temperature.

This hot spring is visible off the road, so bathing suits are highly recommended.

Boat Box is not the only hot spring in the area. You can find others along the Salmon River, including Snake Pit, Cove Creek, Sunbeam Hot Springs, and others.