Best Lassen

Bumpass Hell is a striking mudpot basin within Lassen Volcanic National Park. It’s notable for being the park's largest hydrothermal area characterized by intensely sulfuric steam and boiling mud formations. The area gained its name from Kendall Bumpass, who suffered burns during an encounter with t...

Subway Cave is a walk-through lava tube in Lassen National Forest, California, formed by the Hat Creek basalt flow roughly 20,000 years ago.

Sulfur Works is an active geothermal area located in Lassen Volcanic National Park, California, United States, notable for its boiling mudpots and strong sulfuric gas emissions.

Sulphur Works is a hydrothermal area located along the main road in Lassen Volcanic National Park, California. It represents a remnant volcanic vent on the southwestern flank of Lassen Peak. The site features steaming fumaroles, boiling mudpots, and sulfurous gases visible from a roadside viewpoint.

Devils Kitchen Mudpots lie in California's Lassen Volcanic National Park, within its second-largest hydrothermal area of springs and steam vents.

Subway Cave is an accessible lava tube located in Lassen Volcanic National Park in Northern California. It was created when the outer crust of a basaltic lava flow cooled and solidified while the molten interior continued to flow. The cave is managed by the National Park Service and features a devel...

Sulphur Works Mudpot is a boiling clay pool in California's Lassen Volcanic National Park, formed after steaming ground collapsed in the early 1980s.

Devils Kitchen is a hydrothermal area in Lassen Volcanic National Park, California, noted for acidic hot springs that etch pits into bedrock.

Devil's Kitchen is a distinct hydrothermal area located in the backcountry of Lassen Volcanic National Park in California. Accessible via hiking trails near Juniper Lake, the site is situated in a forested setting that starkly contrasts with the barren ground of the thermal features. The area featur...

Terminal Geyser Mudpots is a hydrothermal area situated within Lassen Volcanic National Park in California. Despite its name, Terminal Geyser is actually a powerful, continuously emitting steam vent rather than a water-erupting geyser. The surrounding area features active mudpots and acidic soils cr...

Terminal Geyser Fumaroles are steam vents in Lassen Volcanic National Park, California; Terminal Geyser is actually a cold stream flowing over a steam vent.

Bumpass Hell is a prominent hydrothermal area located within California's Lassen Volcanic National Park. Named after an early settler who severely burned his leg after breaking through the thin crust, the site is characterized by boiling mud pots, steaming pools, and powerful sulfur-emitting fumarol...

Little Hot Springs Valley Mudpots is a backcountry hydrothermal area in Lassen Volcanic National Park, California, accessible by trail and featuring boiling mud pools.

Pilot Pinnacle is a prominent volcanic fumarole formation in Alaska's Valley of Ten Thousand Smokes that solidified from magma venting during the 1912 Novarupta eruption.

Terminal Geyser is a Lassen steam-vent feature in Warner Valley, notable because it is a cold stream over a vent rather than a true geyser.

Sulfur Works is an accessible geothermal area in Lassen Volcanic National Park, California, marking the vent of a former massive volcano with active gas emissions.

Little Hot Springs Valley is a Lassen hydrothermal area near Sulphur Works, notable for acid-altered red, yellow, and buff volcanic clays.

Big Boiler is Lassen Volcanic National Park's largest fumarole, notable for steam measured as hot as 322 F at Bumpass Hell in California.

Little Hot Springs Valley Fumaroles are steam vents in Lassen Volcanic National Park, California, within a hydrothermal system heated beneath Lassen Peak.