The water that spills over the rims of most hot spring pools in the Rocky Mountains has come up from deep within the earth's crust, super-heated by its proximity to the magma that it passes on it's journey to the surface from unknown depths. Each spring has a distinct mineral content, sometimes overpowering, sometimes almost undetectable. Some are merely warm, others too hot to touch until mixed in lower pools with water from nearby streams or rivers.
Most of the springs occur next to waterways, usually in the bottoms of canyons or valleys. Although there are dozens of commercial resorts that have taken over the once-sacred pools, there are still plenty that are either too remote or are on public land and can only be found by those who know where to look.
I call the non-commercial springs 'naked-hippy-hot-springs' for obvious reasons. If you find company at one of these little-known spots, the said company is usually disrobed, and inclined to love nature and being a part of it. Wearing a bathing suit in one of these springs seems almost as odd as going naked into a public pool. There is something exhilirating and freeing about being in the buff in God's country. Even if there is a buck-naked flabby guy with glasses and an unkempt grey beard soaking quietly in the corner, there is no sense of voyerism. It about as unlike Club Med as one could imagine. The folks who frequent these places are gentle, peaceful, and usually introverted (which is nice, because people usually don't hike for an hour to engage in idle chit-chat).
The water that is healing and calming. Some might call it 'the earth's energy', others might explain that the mineral content and heat has beneficial qualities. Whatever it is, after a good soak (or two or three) it is rejuvinating and incredibly relaxing. The best time to soak is during the cold months, when the snow is falling and the steam rises up out of the pools to obscure the surrounding forest.