The boardwalks weave through and around the Mammoth Hot Springs Terraces – hot pools cascading over travertine terraces are a spectacular sight in the park’s northern section. The disconnected boardwalks, accessible from Grand Loop Road, offer nearly 4 miles of otherwordly hiking:
The terraces would not exist if not for a vast chamber of molten rock, as known as magma, that sits several miles beneath the surface. With enough magma to fill the Grand Canyon 11 times over, even at that distance the chamber warms Yellowstone’s groundwater.
The heated water rises, working its way through fissures to about 50 hot springs at Mammoth. As doing so, it comes into contact with calcium carbonate, forming a weak acid that dissolves the limestone surface.
The result is a series of colorful, ever-changing terraces and pools of steaming hot water, in which temperatures can reach up to 163 degrees F.
Also see:
• Best trails for seeing Yellowstone’s natural wonders
Learn about trail guidebooks available in the Hittin’ the Trail series.
