Mile-16 (Sugah) Hot Spring is located near McCall, ID and features hot springs. The trail is primarily used for hiking.
This is not really a trail. The spring is really close to the road, and you can get to it by a little staircase. It is a great little spring, with blue water and a nice soaking pool with water just at the right temperature.
That said, take a few garbage bags, as some people are just plain ignorant and they insist on littering.