The smooth rock surface makes for a clean and comfortable rock pool that is hard to believe it is a wild hot spring.
There were three main soaking areas.
Lower Pool
Access to Trail Creek Hot Springs is not difficult except during the winter months when it snows.
Therefore, it can be crowded with many visitors.

From the Boise area, head north on State Route 55 and turn right at Cascade.
After entering Warm Lake Road it is about a 30 minute drive.

There is no signage, but it will be easy to find as there is a large parking space on the side of the road.

Hike from the parking lot to Trail Creek, where there are hot springs.

Although the distance is short, it is a steep slope of slippery sand, so comfortable walking shoes are recommended.
At the time of my visit, there were three main pools to soak.

All of them are on the opposite bank of the parking lot and require crossing the river.
However, the river is narrow and there are simple bridges, so this will not be a problem.

The rock pool downstream was pristine.
Although it was the widest, it was too shallow and too tepid to soak due to the inflow of river water.
Central Pool and Source

The central pool features a waterfall of geothermal water cascading over the rocks.

The pool was solid and deep with rocks and mortar.

The inflow of river water was controlled by a valve.

The waterfall, colored with dark green thermophilic algae, was beautiful.

The sources were just up the rock face.

Hot water of 122 degrees F was spewing itself under the rocks in the bushes.

Multiple sources were connected to the trench along the fault plane.



The flow of hot water, which gradually increased in volume, poured down the ditch into the river.
Upper Pool

The upstream rock pool was the smallest, but I liked it best.

The structure was solid rock and mortar and seemed sturdy enough to withstand a few flash floods.

The smooth rock surface continued from the top of the slope to the inside of the pool.

The hot water was distributed through a long, narrow pipe leading to the ditch mentioned earlier.

There was no accumulation of mud, and it appeared so clean that it was hard to believe that it was a wild hot spring.

The water temp inside the pool was 113 degrees F.
There was a valve at the bottom of the pool to draw in river water, which adjusts the temperature well.

I enjoyed the clear, tasteless, odorless water to my heart's content in the comfortable rock pools.

Summary
Trail Creek (Samuel's) Hot Springs, Cascade, Idaho, U.S.
My rating
Type: Undeveloped
Rule: Clothing optional
Chlorination: No
Water temp: Up to 122 degrees F