Lassen Volcanic National Park - Explore the Hydrothermal Areas (U.S. National Park Service)

NPS Photo

This mud pot can be seen from the Bumpass Hell boardwalk.

The remarkable hydrothermal features in Lassen Volcanic National Park include roaring fumaroles (steam and volcanic-gas vents), thumping mud pots, boiling pools, and steaming ground. Water from rain and snow that falls on the highlands of the park feed the hydrothermal system. Once deep underground, the water is heated by a body of hot or molten rock beneath Lassen Peak. Rising hot water boils to form boiling pools and mud pots. Super-heated steam reaches the surface through fractures in the earth to form fumaroles such as those found at Bumpass Hell and Sulphur Works. These features are related to active volcanism and are indications of the ongoing potential for further eruptions from the Lassen "volcanic center."

The areas of hydrothermal activity in Lassen Volcanic include:

Bumpass Hell
Little Hot Springs Valley
Pilot Pinnacle
Sulphur Works
Devils Kitchen
Boiling Springs Lake
Terminal Geyser
Fart Gulch

	Hydrothermal Areas (4 Photos) Album includes photos of Bumpass Hell, Sulphur Works, Terminal Geyser, and Devils Kitchen View Album \| View Slideshow

Hydrothermal Areas (4 Photos)