- 3 miles
- 2 hours
- Trailhead Elevation:
- 8000 feet
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.
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.