This is an easy and fun trip about 30 miles from Jackson, Wyoming.  The hot springs flow out the rocks and into a swimming pool built by the CCC in the 1930's.  There are vault toilets and separate changing rooms.   The web site with directions is at:

 You must have a truck or 4 wheel drive vehicle to get down the 10 mile dirt road approaching the hot springs in the summer.  In the winter, it is accessible by snowmobile.