Mud Volcano & Dragon’s Mouth Hot Spring

A Long History of Wonder

Mud Volcano first drew notice in 1870, when members of the Washburn-Langford-Doane Expedition described a cone-shaped mound that once flung mud as high as the treetops and rumbled loud enough to hear half a mile away. The cone blew itself apart sometime before 1872, leaving the bubbling mud pool visitors see today. Nearby, an unknown park visitor gave Dragon's Mouth Spring its name around 1912, for the surging water and steam that seem to breathe like a dragon from its cave.

Getting There
Distance from Gardiner & North Entrance: 52 miles, ~2 hours
Distance from West Yellowstone & West Entrance: 50 miles, ~2 hours

Mud Volcano sits on the Grand Loop Road between Canyon Village and Fishing Bridge, at the south end of Hayden Valley. From the North Entrance at Gardiner, the drive passes Mammoth Hot Springs, Norris, and Canyon Village; from the West Entrance at West Yellowstone, it runs through Madison Junction, Norris, and Canyon Village. Either way, it's a straightforward stop along the lower loop.

What You'll See

A short boardwalk loop connects the churning, gray Mud Volcano pool to Dragon's Mouth Spring next door, where surging water and steam produce a booming, growling sound from deep in a hillside cave. A longer loop continues past Black Dragon's Cauldron, Sour Lake, Grizzly Fumarole, and Sulphur Caldron, one of the most acidic springs in the park.

Visitor Tips

Dragon's Mouth Spring is the owner's personal favorite feature in the whole park, so it's worth lingering at the boardwalk railing to listen as much as look. Expect a strong rotten-egg smell from hydrogen sulfide gas throughout the area, and note the short loop is wheelchair accessible while the longer one has a steep paved climb. This stop pairs naturally with a drive through Hayden Valley just to the north, one of the best wildlife-watching stretches in the park.