Postcard of Jupiter Terrace photographed by Asahel Curtis, 1928. Jupiter Terrace displays cycles of activity. In the 1980s Jupiter Terrace flowed so heavily that it overtook boardwalks several times. It has been dry since 1992, but when active, its color and intricate terraces make Jupiter an appealing spring. Mammoth Hot Springs is a large complex of hot springs on a hill of travertine in Yellowstone NP 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. Yellowstone National Park is a national park located primarily in the state of Wyoming, although it also extends into Montana and Idaho.