Trail Creek Hot Springs

Trail Creek Hot Springs is a hugely popular pair of mortar-reinforced rock pools in the Boise National Forest northeast of Cascade, in the Warm Lake area. A short but steep hike from the highway pullout — across a man-made bridge over the creek — reaches two pools whose temperatures soakers fine-tune with creek water and a valved PVC feed. Expect company: usage here is extreme.

The Pools

Pool 1 is about 10 feet wide and 3 feet deep, fitting roughly 10 soakers. Mortar reinforces its rock walls; the bottom is rock and sand. Hot water slides down algae-covered rocks into the pool, and cold creek water is mixed in by moving rocks at the inlet to set the temperature. Late in the summer this pool can become stranded and may need an intake hose. Pool 2, just past the first, is about 8 feet wide and 2.5 feet deep (roughly 6 soakers), with mortar and rock walls. Hot water bubbles up through its sandy bottom, supplemented by a PVC pipe feeding from the source above Pool 1; temperature is adjusted with a valve on that pipe near the source.

Seasonal Notes

The lower pool submerges during spring runoff; the upper pool’s tall mortar walls stand up to the creek better. In winter, a 4×4 is sometimes needed for the last leg of the Warm Lake Highway, and the highway occasionally closes in severe winter weather.

Camping

Ample level campsites with fire rings sit just above the hot springs, below the highway pullout — expect to share. Additional National Forest campgrounds are nearby, and Warm Lake itself is close.

Trail Creek Hot Springs in Idaho