• Grand Prismatic Hot Spring


Hot Springs and Mudpots

Hot springs and mudpots are some of the most common types of geothermal activity in Yellowstone National Park.

Hot springs are heated from beneath the surface of the water. Mudpots are acidic hot springs, many of which produce a rotten egg smell (hydrogen sulphide) while breaking rock down into clay. The largest hot springs in the USA, the Grand Prismatic Spring, is found here, featuring vivid oranges, yellows and blues around the edges of the mineral-rich water produced by pigmented bacteria.

Explore the multi-coloured Mammoth Hot Springs Terrace from an elaborate network of boardwalks over the springs. You can also witness the natural wonder of Fountain Paint Pots, so named for its assortment of reds, yellows and browns in the mud, and located in the Lower Geyser basin of Yellowstone.