|Atop Lassen's plug dome, with Shasta in the background|
Difficulty: Moderate, with short scramble at the end to reach summit; this hike begins at a high altitude and goes even higher.
Access: Paved road to a large trailhead parking lot. As of autumn 2015, Lassen Volcanic National Park entrance fee is $20.
Lassen Peak has the distinction of being the second tallest peak in northern California, the southernmost major Cascade volcano, and one of only two volcanoes in the contiguous United States to erupt in the twentieth century. Even though the summit tops out at 10,457 feet, the trail to the top is a fairly simple day hike that can be tackled by most reasonably fit people. The rewards are a close-up look at the summit crater of a plug dome volcano that last erupted less than a hundred years ago and sweeping views of the south Cascades, Central Valley, Coast Ranges, northern Sierra Nevada, and the Great Basin. The final scramble at the end is slightly more challenging, but even those who skip the scramble can still enjoy most of the fine views from the false summit. You'll want to bring sunscreen on this hike: most of the trail is quite exposed, with only minimal tree cover during the first part of the hike.
Lassen Volcanic National Park is a decently long way from anywhere, unless you live in or are visiting Red Bluff, California. It's a four-hour drive from the Bay Area to the trailhead when there's no traffic, with an endless stretch of passing by hazy cropland on I-5.
The trailhead is a vey sizable parking lot near the high point of the Park Road. The summit isn't visible from the trailhead, but it is possible to look up the barren, rocky slopes to see Vulcan's Eye, a prominent and instantly recognizable geological feature halfway up the mountain's south slope.
I hiked this trail with three friends after camping the night before at Manzanita Lake and spending the morning exploring Bumpass Hell. After lunching at Lake Helen, we made the short drive over the trailhead and started up the barren trail through a valley of loose dacite. Vulcan's Eye towered above us: it was as if the mountain itself was gazing upon the approaching hikers with suspicion. After reaching the foot of the main slope, the trail made a switchback, with a sign at the switchback discouraging hikers from cutting switchbacks and heading straight up the slope.
The long first switchback brought us onto the slopes of the mountain itself and we began an ascent towards the northeast. Here, a sign informed us that Vulcan's Eye is actually a former conduit for lava that has since solidified.
|Lassen Peak, Vulcan's Eye|
|Reading Peak and Lake Almanor|
|The ascent up Lassen|
A short walk along the ridge brought us to the false summit, from which we could look straight down into the summit crater left from the eruptions of the early twentieth century. The crater looked less like traditional ideas of a steaming volcanic pit and instead looked more like a rubbish heap of dacite and ash. Four annotated placards detailed the views in all directions. Many hikers ended their hike here, but we decided to continue to the true summit, which rose less than a hundred feet more to the east of the false summit.
|Final section of trail and scramble to the peak|
Mt. Shasta, a great stratovolcano that is the second tallest of the Cascade volcanoes, rose to the north. Joaquin Miller once described Shasta as "lone as God, white as a winter moon," a description that was a little less apt during one of the driest seasons in California ever. Although some glaciers on its south slopes were still visible, the peak seemed largely denuded of ice.
|The glaciated cone of Mt. Shasta in the distance|
Signs of volcanism weren't limited to Lassen itself: to the east were Prospect Mountain and Mt. Harkness, both gently-sloped shield volcanoes active in some geologically recent but anthropologically distant past. The Cinder Cone and the Fantastic Lava Beds were visible near the south end of Butte Lake. One wonders if the formation of Cinder Cone followed a simular script to that of Paricutin in Mexico: that of a crack in otherwise nondescript earth very suddenly bursting forth into a fountain of hot rock, catching unaware any farmers (or foraging wildlife) nearby.
In fact, there are few places like Lassen to see the different manifestations of volcanism. Lassen Peak is itself a dacite plug dome, with occasional explosive eruptions but formed primarily from the solidification of some fairly silicic and viscous lava that blocks an underlying source of extrusion. Brokeoff Mountain, to the southwest, is the remnants of the collapsed Mount Tehama, once a great stratovolcano composed of layered lava and ash flows; Mt. Shasta, visible far to the north, formed through a similar process, as did most of the other well-known Cascade volcanoes. Cinder Cone is, appropriately, a cinder cone: formed from explosive eruptions that deposit a hill of ash and volcanic rocks around the source of volcanism. Harkness and Prospect, both shield volcanoes, arose through eruptions of less viscous lava, which pooled out and created gentle slopes leading up to their summit craters.
|Chaos Crags and the Devestated Area|
|Cinder Cone and the Fantastic Lava Beds|