Lower Terraces - Middle Trailhead

This trailhead starts partway up the Lower Terraces, with boardwalks leading to both Liberty Cap and Palette Spring at the base of the Lower Terraces to the north and Minerva Spring & Terrace to the south. The boardwalk and trail continues into the Lower Terraces, providing views of older, inactive terraces as well as active springs like the top of Palette Spring and New Blue Spring. Mammoth Hot Springs A network of fractures and fissures form the plumbing system that allows hot water from underground to reach the surface at Mammoth Hot Springs. Small earthquakes may keep the plumbing open. The water comes from rain and snow falling on surrounding mountains and seeping deep into the earth where it is heated. The volcanic heat source for Mammoth Hot Springs remains somewhat of a mystery. Scientists have proposed two sources: the large magma chamber underlying the Yellowstone Caldera or a smaller heat source closer to Mammoth. For hundreds of years, Shoshone and Bannock people collected minerals from the Mammoth Hot Springs terraces for white paint. Travertine Terraces Travertine terraces are formed from limestone (calcium carbonate). Water rises through the limestone, carrying high amounts of dissolved calcium carbonate. At the surface, carbon dioxide is released and calcium carbonate is deposited, forming travertine, the chalky white rock of the terraces. Due to the rapid rate of deposition, these features constantly and quickly change. Accessibility Transitions from asphalt walkways to boardwalks may require assistance. Some sections of boardwalk are wheelchair-accessible. The rest of the area has stairs or steep grades due to terrain. Distance from parking in front of Liberty Cap to the end of the boardwalk at Palette Spring is approximately 135 yards. Use Caution in Hydrothermal Areas Stay on boardwalks and designated trails. Hydrothermal water can severely burn you. Never run, push, or shove. Supervise children at all times. Do not scratch hydrothermal mats. You are responsible for your safety. Think safety, act safely. Yellowstone is a dangerous place.