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 - A 16 acre bowl of activity viewed from a boardwalk and the largest hydrothermal area in the park. A 3 mile round-trip hike is required.

Little Hot Springs Valley - Located at the bottom of a steep valley, steam vents can be viewed via the park road with binoculars. There is no hike.

Pilot Pinnacle - There is no hike or parking area. Features include steam vents, boiling pools and mudpots.

Sulphur Works - The most easily accessed area; boiling mudpots, and steam vents can be viewed via a sidewalk.

Devils Kitchen - Located in Warner Valley via a hiking trail; features include steam vents, mudpots and boiling pools.

Boiling Springs Lake - Located in Warner Valley - A number of steam vents are located under Boiling Springs Lake, keeping the temperature of the lake around 125 degrees. A number of mudpots line part of the shore.

Terminal Geyser - Located in Warner Valley - Not a true geyser, but a steam vent with water running over the top give the appearance of a geyser.

	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)

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