The Michelin Guide's review
Transformations brought upon by nature are clearly visible on the stepped terraces of the Mammoth Hot Springs! The springs, which only reach a temperature of 170°F, deposit 2t of calcite here every day. Following a series of chemical reactions, a natural deposit with striking colours is formed. The travertine Opal Terrace, which is grazed by elk, rivals that of the Minerva Terrace, a maze of tiny falls and multicoloured terraces, and the strange stalactites of the Canary Spring.