Hiking Bumpass Hell Trail
Trail Opening Information
Previous trail opening dates: July 13, 2011 | June 29, 2012 | June 25, 2013 | June 11, 2014
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.
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.
Many thanks to John Crossley for contributions to this webpage.