Mammoth Hot Springs is Yellowstone’s most sculptural thermal area. It is a hillside of travertine terraces five miles south of the North Entrance, beside the historic park headquarters at Mammoth. Hot water rises through ancient limestone, dissolves calcium carbonate, and redeposits it as stair-stepped white and amber ledges that change shape year after year.
Roughly 1.75 miles of boardwalks climb the Lower Terraces past Liberty Cap, a 37-foot dormant spring cone, along with Palette Spring and the shifting flows of Minerva and Canary Springs. Heat-loving microbes streak the runoff channels orange, brown and green. Active vents move constantly, so a terrace that steamed last season may sit dry and chalk-gray today. Above, the one-way Upper Terrace Drive loops through Orange Spring Mound and stands of trees partly buried in travertine. Elk often graze the lawns of Fort Yellowstone, the former U.S. Army post next door.
Visitor Highlights & Practical Info
Arrive before 9 a.m. or after 5 p.m. in summer for open parking and soft, low-angle light on the terraces. Cold mornings in fall and winter produce the most dramatic steam. The road from the North Entrance through Mammoth stays open year-round, but Upper Terrace Drive closes to cars in winter. Stay on the boardwalks, because the crust is thin and the water can scald. Keep at least 25 yards from elk. Stop at the Albright Visitor Center, housed in a Fort Yellowstone stone building, for trail and wildlife updates. Gardiner, Montana, sits just outside the North Entrance for lodging and food.
