Lassen Volcanic National Park

Lassen Volcanic National Park is in northern California, about three hours from Sacramento. It is one of the few places on earth where all four types of volcanoes stand in a single park, crowned by Lassen Peak, the largest plug dome volcano in the world. Bumpass Hell bubbles with mud pots and steaming fumaroles, the park's largest hydrothermal basin. Best season is summer: July through September brings open roads and snow free trails.