Upstate California’s Lassen National Volcanic Park, home of those eponymous volcanoes, plus wildflower-strewn meadows, clear mountain lakes, and looming peaks, can also boast of one of the most otherworldly natural phenomena in any national park: Bumpass Hell. It may have an extreme ring to it, but the “hell” in the name is apt. Here you see geology in action—16 acres of boiling springs and mud pots, hissing steam vents, and roaring fumaroles.
Early pioneer Kendall Vanhook Bumpass was the unfortunate explorer who stumbled—literally—upon these hydrothermal features in the 1860s: the discovery included stepping through the thin crust of a boiling mudpot and severely scalding his leg, leading to its eventual amputation.
No such worries for visitors today. A well-marked, three-mile round-trip trail from the Bumpass Hell parking area, seven miles from the park’s southwest entrance, leads visitors to the geothermal site. Along the way, a short spur trail leads to a stunning panorama of peaks—actually the remnants of a massive volcano called Mount Tehama, which exploded some 500,000 years ago. As you walk along what resembles a desert boardwalk, colorful soils begin to come into view, along with unnaturally (by normal standards) turquoise pools.
It’s your nose, though, that will tip you off first when you near Bumpass Hell. The rotten-egg smell from naturally occurring gases rising from the mineral-rich waters is pervasive, and so is the noise—a strange ruckus created by all the belching mud pots and bubbling pools. The temperature of the high-velocity steam emitted from Big Boiler, the largest fumarole in the park, has been measured to be as hot as 322 degrees Fahrenheit, making it one of the hottest fumaroles in the world. Bumpass Hell’s elevated trail lets you walk safely around it and the rest of the dangerous but wondrous geothermal oddities, unlike poor Mr. Bumpass.
When planning your visit, keep in mind that during winter, the higher elevations of Lassen can get up to 30 feet of snow. The best time to visit the park is between July and October.