Bumpass Hell

Bumpass Hell is the showpiece of Lassen's geothermal world and one of the largest hydrothermal areas in the Cascades. A moderate hiking trail of roughly three miles round trip leads from a trailhead on the park road across a ridge with views of Lake Helen and Lassen Peak, then descends into a steaming basin where boardwalks wind among boiling mud pots, hissing fumaroles, bubbling springs and pools of green and turquoise water. The area is named after Kendall Vanhook Bumpass, a nineteenth-century guide who badly burned his leg after breaking through the thin crust, and the lesson from his story is still the first rule of the visit: stay on the boardwalks and trails at all times. The ground here is thin and the water scalding, and the park enforces the rule strictly for good reason. The smell of sulphur is strong, the steam clouds drift with the wind, and the colours of minerals and algae make it a favourite for photographers. Allow around two to three hours, including time at the basin.

The trail is straightforward but not trivial. It begins at about eight thousand feet, so the altitude is noticeable on the climb back, and the path includes some stairs and a gradual grade. Wear sturdy shoes, bring water, sunscreen and a hat, and keep children close and dogs at home, since pets are not allowed on park trails.

In early summer, snow patches may linger on the trail and the boardwalk may be closed, so check with the National Park Service for current conditions and advisories before you set out. Midsummer to early autumn is usually the best window.

The hydrothermal system is the visible part of a volcanic plumbing network. Rainwater and snowmelt seep deep underground, are heated by magma beneath the Lassen area and rise back to the surface as steam, gases and boiling water. That explains the variety: fumaroles are vents of steam and gas, mud pots form where acidic water breaks down rock into clay, and the springs and pools have different colours depending on their chemistry.

A ranger-led walk, offered in some seasons, adds geology and history, and an audio tour of the park road can give background before you arrive.

Plan the visit in the context of a Lassen day. Most visitors combine Bumpass Hell with the park's scenic drive, Lake Helen and a short walk at the Devastated Area, while strong hikers add the Lassen Peak trail. Arrive early in summer to avoid crowds and afternoon heat, and expect the parking area to fill by late morning on weekends.

The park charges an entrance fee, and facilities are limited near the trailhead, so bring snacks and water. The trail is among the park's most popular for a reason, and the combination of effort and payoff makes it one of the highlights of a trip to Northern California.

Combine the walk with the rest of the park road, but start here early. The parking area fills quickly in July and August, and the basin is calmer, cooler and easier to photograph before the day-trippers arrive. Carry a lightweight jacket because steam and breeze can chill you, avoid wearing sandals, and do not put hands into any water. Respect closures and signs, which change as thermal activity shifts.