Since the days when saber-toothed tigers and woolly mammoths roamed North America, melting snow has trickled through hidden fissures deep in the Rocky Mountains. The icy water flows through limestone cracks into subterranean hot springs, percolating over five thousand feet below the earth’s surface.
Over thousands of years, limestone deposits formed and shifted, creating a dome above the bubbling water. The mound is made of tufa—calcium carbonate—and reaches almost sixty feet into the sky. The thermal spring appears bright blue in the sunlight shafting down through the top of the dome. Well over a century ago, silver miners from places like Ireland and Scandinavia sought out these hot springs after grueling work in the mines of Park City. We swam in this celebrated hot pot, which maintains a steady temperature between 90 to 96 degrees.