Geology of the Lassen Country
The Bumpass Hell Trail is one of the most popular destinations in the Lassen Country. The trailhead is at the large parking area 0.25 mile (0.4 km) east of Lake Helen. The trail traverses the dacite of Bumpass Mountain for the majority of the hike. Also, note the well-preserved glacial polish and striae in the dacite alongside the first few hundred yards of the trail. They were created by the glacier that started from the Lake Helen cirque. At the viewpoint where the trail turns east, about 0.5 mile (0.8 km) from the trailhead, it crosses briefly into andesite of Mount Diller. Here a National Park Service trailside interpretive display shows a model of Brokeoff Volcano before erosion.
Trailhead: Bumpass Hell trailhead parking lot
Distance: 3.0 miles (4.8 km) round trip
Key Geologic Features: Hot springs, clay-altered bedrock
