Monday, December 28, 2015

Lassen Peak

Atop Lassen's plug dome, with Shasta in the background
5 miles round trip, 2000 feet elevation gain
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
Though trees occasionally lined the trail, we were mostly out in the open on Lassen's south slopes, which provided us with excellent views to the south of nearby Reading Peak and faraway Lake Almanor. As we ascended, the heart shape of Lake Almanor became more and more apparent, while Reading Peak, which dominated the nearby landscape when viewed from the lower slopes, shrank to just another bump below the horizon.

Reading Peak and Lake Almanor
Meanwhile, the trail picked up its pace and began a moderately steep and steady ascent using a series of increasingly short switchbacks. Brokeoff Mountain and the other remnant peaks of the former Mount Tehama were soon visible in the west. As we climbed higher, we began to catch glimpses of the Central Valley, which was intially blocked by closer peaks.

Brokeoff Mountain
We made quick progress and soon found ourselves about halfway up at a sharp switchback with a view of the entire southeast face of Lassen Peak. From here, we could look up and see the trail switchbacking continuously up a ridge towards the summit. The trail here was remarkably well built, with stone walls and stone steps occasionally making travel a bit easier.

The ascent up Lassen
Further up the steady switchbacks, the number of trees along the trail dwindled. Those trees that could survive the exposure high on Lassen's slopes had been sculpted by the wind into grotesque krummholz, their branches twisting to find leeward shelter.

As the switchbacks continued, the views improved. The sapphire-blue waters of Lake Helen were soon fully visible, as were Juniper and Butte Lakes to the west. Pine forests stretched to the horizon to the south while the barren, arid mountains of the Great Basin came into distant view in the east.

Lake Helen
The trail often left us a little breathless, and not just from the wide views: the endless switchbacks had brought us to over 10,000 feet above sea level, where the air was substantially thinner. Each trailside placard indicated that we were a little closer to the summit, until we finally reached the summit ridge about an hour and a half after leaving the trailhead. The croplands of California's Central Valley was laid out beneath us and across the valley we could see the sharp peaks of the Trinity Alps. Views to the southwest were unfortunately limited by smog in the valley.

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
We followed a path into the saddle between the peaks, passing the last patches of snow left over from snowstorms of years past (certainly not snow from the previous drought winter). The well-defined path petered out at the peak, so we scrambled in the general direction of the summit. Soon, we were atop the second highest peak in Northern California with hundred-mile views in nearly every direction.

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
Scrambling to the east side of the peak, we found concrete blocks and a flat platform, remnants of a former weather station. From here, we surveyed the eastern part of Lassen Volcanic National Park. The most noticeable feature was the barren eastern slope of the mountain: this was the area devastated by the series of eruptions in the 1910s, including the most violent eruption in 1915, that helped to shape build the summit crater and the eastern slopes of Lassen Peak. This eruption was one of only two in the contiguous United States in the twentieth century, and was the first eruption in the US to be documented by photographs. These eruptions and the opportunities for scientific research that they provided were the impetus for transforming this otherwise quiet Northern California landscape into a national park.

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
We spent a half hour at the summit before making our return. At the bottom of the summit block, a few hikers informed us that great views were to be had at the north end of the summit crater- where I'm sure Manzanita Lake would have been visible- but we decided to skip the view in order to make it back to the Bay Area in time that night.

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