There is a 0.5 mile loop trail at the Devastated Area at Lassen Volcanic National Park (CA) appropriately named the Devastated Area Trail. The trail is an easy hike with a number of information signs teaching about the rocks left behind from Lassen Peak’s 1915 eruption. One of the most interesting of these I found were the puzzle rocks which had the following description sign by them:
After the May 19 avalanche carried hot lava rocks, the surrounding air temperature quickly cooled them. As they cooled — from the outside in — some of the rocks fractured internally, breaking into pyramid-like shapes. Like a jigsaw puzzle, many of the pieces could easily be reconfigured — solving a hot puzzle from the past…
As the description indicates and the photos show, these rocks really do look like puzzles that could easily be shaped back together with a bit of effort. I always enjoy finding tidbits of information like this when I travel to the various National Parks.
I plan to camp at Lassen Volcanic National Park in October, 2011 but the reservable campsites are all full. Manzanita Lake Campground has some campsites for walk-up only. I am wondering if I arrive on Friday, will the walk-up campgrounds be filled?
The likelihood is better than if it was the heart of summer but there is really no way to know for sure. Obviously, the earlier in the day you can arrive, the more likely that a spot will be available.