Lower Minerva Terrace, Yellowstone National Park Postcard

"Lower Minerva Terrace, Yellowstone National Park, Wyoming" by Catherine Sherman. The terraces of the lower section of Minerva Terrace form a beautiful pattern. Mammoth Hot Springs is a large complex of hot springs on a hill of travertine in Yellowstone National Park adjacent to Fort Yellowstone and the Mammoth Hot Springs Historic District. It was created over thousands of years as hot water from the spring cooled and deposited calcium carbonate (over two tons flow into Mammoth each day in a solution). Although these springs lie outside the caldera boundary, their energy has been attributed to the same magmatic system that fuels other Yellowstone geothermal areas.