There is a fun hot springs complex located at the end of a bumpy road in the Bridger-Teton National Forest, near Hoback, WY. (GPS: 43.369727, -110.445553)
The main attraction is the developed, pay-to-soak facility above Granite Falls. The naturally hot mineral water ranges from 93-112 F. The pool is hottest near the spring. If you move around a bit you can usually find a spot for your comfort level. There is an $8 admission fee (cash only). Bathrooms and changing rooms are located on-site.
There are two undeveloped, free, small hot pools below the waterfall that can accommodate small groups. You have to wade across the stream to reach them.
This area is remote. No cell service or other services. The road is not plowed or maintained during winter but the developed facility stays open to people arriving by over-the-snow vehicles. You can also access the undeveloped pools, if you can get across the cold river.
A developed campground is located just downstream from the pools and is open during summer months. Dispersed camping is allowed downstream from the campground.
The area is scenic and attracts a good number of visitors. It is worth stopping.