Lassen National Park
Lassen Volcanic National Park is in northern California. It's rich in hydrothermal sites like Bumpass Hell, with its acres of bubbling mud pots. The summit of Lassen Peak Volcano offers views over the surrounding wilderness. Nearby, the Devastated Area is littered with lava rocks from its last eruption. A network of trails through forest and around several lakes connects with the Pacific Crest Trail in the north.