Bumpass Hell Trail

View of Bumpass Hell boardwalk winding through thermal areas with grey and yellow thermally altered earth.

Start: Bumpass Hell parking area
Round Trip Distance: 3 miles
Round Trip Time: 2 hours
Terrain: easy 300 foot descent
Elevation: 8000 feet


2018 Trail Closure

To ensure the safety of both staff and visitors, a closure area will be in effect for the Bumpass Hell Trail from April 1, 2018 through December 1, 2018.

  • The Bumpass Hell Trail is closed at the Bumpass Hell and Lake Helen parking areas.
  • Access to the Bumpass Hell Basin from the Cold Boiling Lake Trail is open. Learn more here.
  • The closure area includes slopes above and below the trail to help prevent injury to visitors or staff from rockfall.
  • It is unlawful to enter a closed area; violators may be ticketed.
Map of closure area (shown in opaque red fill) for the Bumpass Hell Trail and basin
Map of Bumpass Hell Trail and Basin closure area depicted in an opaque red fill.

Alternatives to Visiting Bumpass Hell

There are numerous opportunities to view hydrothermal features in the park during the Bumpass Hell Trail and Basin closure. Here are a few suggestions:

  • Visit Sulphur Works hydrothermal area. The sidewalk provides views of boiling mudpots, steam vents, and steaming ground. You can also hike a short distance up the Ridge Lakes Trail, from the Sulphur Works parking area, for an alternative view.
  • View contemporary and/or historic images of the Bumpass Hell hydrothermal area or view the video below. A webcam stream from the basin overlook is anticipated to be available in May or June (dependent on access and technical constraints).
  • Hike Boiling Springs Lake or Devils Kitchen Trails in the Warner Valley area (accessed via Chester) to these equally impressive hydrothermal areas. Expect an increase in parking demand and trail use this summer.
  • Access the eastern overlook of Bumpass Hell Basin via a 5.2-mile round-trip trail from Kings Creek Picnic Area via Cold Boiling Lake. Parking will be extremely limited. View photos and learn more here.
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Learn more about the trail into Lassen's largest and most popular hydrothermal area, Bumpass Hell.


Seasonal Trail Opening Information

The trail to reach Bumpass Hell is at a high elevation and recieves significant snowpack. Every spring, the trail will close due to severe winter hazards. On average, it opens by Fourth of July weekend each summer, however actual opening dates vary with each year's snow pack. For more information about Bumpass Hell trail status and conditions, please contact the visitor center (530) 595-4480.

Previous trail opening dates: July 13, 2011 | June 29, 2012 | June 25, 2013 | June 11, 2014 | June 7, 2015 | July 9, 2016 | August 22, 2017 | Trail Closed in 2018


The Largest Hydrothermal Area in the Park

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. 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. Learn more about hydrothermal features in Lassen in a U.S. Geological Survey publication, "Hot Water" in Lassen Volcanic National Park.

Last updated: November 3, 2018

Contact the Park

Mailing Address:

PO Box 100
Mineral, CA 96063


(530) 595-4480

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