Impressive Lassen Volcanic National Park has steaming hydrothermal sulfur pools and cauldrons that can be seen from the boardwalk in Bumpass Hell. At 10,457ft Lassen Peak is one of the world's largest plug-dome volcanoes. In total, the park has 150 miles of hiking trails, including a 17-mile section of the Pacific Crest Trail.
Experienced hikers can attack the Lassen Peak Trail; it takes at least 4½ hours to make the 5-mile round trip but the first 1.3 miles up to the Grandview viewpoint is suitable for families. The 360-degree view from the top is stunning, even if the weather is a bit hazy. Early in the season you’ll need snow and ice-climbing equipment to reach the summit. Near the Kom Yah-mah-nee visitor facility, a gentler 2.3-mile trail leads through meadows and forest to Mill Creek Falls. Further north on Hwy 89 you’ll recognize the roadside sulfur works by its bubbling mud pots, hissing steam vent, fountains and fumaroles. At Bumpass Hell a moderate 1.5-mile trail and boardwalk lead to an active geothermal area, with bizarrely colored pools and billowing clouds of steam.
The road and trails wind through cinder cones, lava and lush alpine glades, with views of Juniper Lake, Snag Lake and the plains beyond. Most of the lakes at higher elevations remain partially and beautifully frozen in summer. Leave time to fish, swim or boat on Manzanita Lake, a slightly lower emerald gem near the northern entrance.
Astronomy buffs and recreational stargazers make a point of visiting the park at night. The area's natural darkness offers a prime opportunity for viewing the Milky Way and other celestial wonders, and during a weekend in August, there's even a Lassen Dark Sky Festival.