Mammoth Hot Springs in Yellowstone National Park is a vast geothermal complex where mineral-rich hot water rises through limestone, cools, and deposits travertine terraces that have built up over thousands of years. Fed by water believed to travel underground from Norris Geyser Basin and heated by the same magmatic system as Yellowstone’s other thermal areas, the springs produce more than two tons of calcium carbonate daily and emerge at about 170 °F. Famous features such as Minerva Terrace show how constantly the system changes, with algae coloring the deposits and earthquakes sometimes shifting vents. The landscape also preserves glacial features, while Hotel Terrace later supported the Mammoth Hotel and Fort Yellowstone.