Bumpass Hell is the largest concentration of hydrothermal features in the park.  Bumpass Hell was named after an early settler who severly burned a leg after falling into a boiling pool.  The hydrothermal features can be reached today from a well-marked 1.5 mile trail that starts from a parking area opposite Lake Helen.  A visit to Lassen is not complete without a stop at Bumpass Hell.

The Trail: The trail is quite easy, though the altitude (8,000 feet) can make the trail seem moderately difficult.  Hiking boots are recommended as the trail crosses generally rocky land with some tree cover, and without much change in elevation until the 100 foot drop into the thermally active basin. The active area can be seen (and smelt!) from far away - a wide basin filled with various steaming pools and unusual multi-colored soils, stained orange, brown, yellow and green by sulphur and other minerals. Together with the occasional white snow patches, the (usually) deep blue sky and the aquamarine waters, the spectacle is extremely beautiful and colourful.

Because of the popularity of this trail, it is usually opened around July 1st.  In heavy snow years deep snow on the trail can last past July 1st making the trail hazardous for use.  On these years the opening has to be postponed.   You can always call the visitor center for current trail conditions at 530-595-4480.

Bumpass Hell is the largest hydrothermal area in the park, and marks the principal area of upflow of steam and discharge from the Lassen hydrothermal system (see illustration in photo gallery below). The temperature of high-velocity steam jetting from Big Boiler, the largest fumarole in the park, has been measured as high as 322°F (161°C), making it one of the hottest fumaroles in the world. The steam heated waters are typically acidic and are not safe, even for bathing.  Please stay on the trail and boardwalks for your safety.

Many thanks to John Crossley for contributions to this webpage.