Although Mystic Hot Springs' titular water source has been flowing for millions of years, and the site has been inviting people to have a soak in the hot waters for over century, it wasn't until the 1990s that the bathtubs showed up.
The current incarnation of the Mystic Hot Springs was established by self-described "Producer/Director/Artist" Mike Ginsburg. He stumbled upon the resort on his way back from some Grateful Dead shows in Las Vegas, and straight up bought the resort. Using his free spirit and artistic drive, Ginsburg created a number of new soaking and floatation areas, including the resort's iconic soaking bathtubs, which he installed right into the land as though they occurred naturally.
Today the springs are still welcoming those with a free spirit, who would like to relax in the natural minerals bubbling up from the ground. There are around eight soaking pools of varying heat, as the water cools a bit as it travels to the various pools. There are also a pair of larger pools, one deep and one shallow, for visitors to take a dip in. Ginsburg will also administer his unique brand of massage he calls, "transflotation massage."
If you want to visit, you can camp, or stay in an RV, or shack up in one of the handful of cabins and fitted busses. No matter where you stay, the experience will likely be mystic.