Three-mile Hot Spring, also called Sulphur Hot Spring for extremely obvious reasons, is a little-visited spring north of the town of Wells, and can be a less-crowded alternative to the popular and rutted-access pool up at Twelve-mile Hot Spring.
Three-mile Hot Spring lies at the bottom of a rocky mountainside. The source gushes from a crack in the stone at about 103 degrees and cools a couple degrees throughout the rest of the pool. A stone wall helps contain the water that is about thigh-deep in the center of the spring.
The water has a milky emerald hue, though this obscures the pool and makes it impossible to see beneath the surface, so easing into the algae-slicked stone is a must. Water from the spring flows out near the center of the pool and into a marshy area, though the lack of circulation on the far side creates a surface full of thick algae and mineral buildup. This is easy enough to avoid by sticking to the moving water near the source.
The negative about this is spring is that it is highly sulfurous. You WILL smell of sulfur for the rest of the day after a soak here. But if you can handle that, and you can manage to dodge the cow piles left near the springs, it really is a scenic spot to soak. Homeowners lie within view of the spring, so nudity may not be a good idea here.
The area around the springs is marshy and saturated, so it is best to park before the marshy area. From here you can look toward the exposed rock and the base of the mountainside and walk to it, about .15 mile away. There are no amenities of any kind near Three-mile Hot Spring.