Sight · Lassen Volcanic National Park
A mudflow carried this boulder down Lassen Peak in 1915.
Overview
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The highest, rockiest slopes around here are a summer buffet for grizzly bears.
Lassen Volcanic Tour Guide
Parkwolf is a GPS audio tour guide for Lassen Volcanic National Park. As you drive, it chimes in with what’s ahead: hidden gems, upcoming stops, history, geology, and wildlife, right through your car’s speakers.
See the Lassen Volcanic audio tourRecorded for this place
Hot Rock: A Boulder That Stayed Hot“You're coming up on Hot Rock, a boulder swept down from Lassen Peak by a volcanic mudflow.”
Plays as you drive up to Hot Rock in the Parkwolf Lassen Volcanic Tour Guide.
More stories near here in the app
“Fantastic app with many points of information… It’s great to just turn on while you’re driving and it gives you an audio tour of the national Park. We love it!!!!”
Guide
Hot Rock is a large volcanic boulder beside Lassen Volcanic National Park Highway, carried down from Lassen Peak in the 1915 eruption. It is a short interpretive pause for anyone curious about how far the eruption reached; save a longer stop for a trail or hydrothermal area. The rock is no longer hot: its name comes from what visitors reported in the months after the eruption.
The boulder had been in Lassen Peak’s vent before a lahar—a fast-moving slurry of mud, earth and rock—swept it downslope. As it traveled, its interior was estimated to be near 1,000°F. Visitors reported that it stayed hot to the touch for months afterward.
Benjamin F. Loomis photographed Hot Rock during the 1915–16 eruption. A once-forested slope was stripped bare in a single day; more than a century later, forest regrowth hides many of the smaller rocks from the event. Frame the boulder with the pines around it: that regrown landscape is part of the story.
Wildlife
103 sightingsBlack BearMost seen around 7 PMSighting map
44 sightingsBald EagleMost seen around 7 AMSighting map
348 sightingsMule DeerMost seen around 7 PMSighting map
17 sightingsSandhill CraneMost seen around 6 AMSighting map
47 sightingsGreat Blue HeronMost seen around 7 AMSighting map
12 sightingsGreat EgretMost seen around 7 AMSighting mapSighting maps show where each species has been reported across Lassen Volcanic. Wildlife moves, so no sighting is guaranteed.
Keep exploring
EasyDevastated Area Interpretive Trail0.3 mi · 20 min · 1.9 mi awayA quick accessible loop among the rocks left by Lassen's 1915 eruption.
ChallengingHat Creek Headwaters Trail6.1 mi · 5 hr · 2.2 mi awayA shuttle hike from creekside falls to meadow and lake country.ModerateHat Lake to Paradise Meadows Trail2.8 mi · 2 hr · 2.2 mi awayA shaded creek climb to a meadow beneath Lassen’s rocky cliffs.
ModerateNobles Emigrant Trail: Hat Lake to Butte Lake13 mi · 5.5 hr · 2.2 mi awayA historic forest traverse opens onto Cinder Cone’s volcanic landscape.
ModerateCrags Lake Trail4 mi · 2.5 hr · 3.6 mi awayRocky Chaos Jumbles give way to a high view of Crags Lake.
EasyLily Pond Interpretive Trail0.8 mi · 1 hr · 3.7 mi awayAn easy, interpretive loop through pond, meadow and volcanic forest.
ModerateManzanita Creek Trail7 mi · 4 hr · 3.8 mi awayA forest creek climb to a marshy meadow beneath Loomis Peak.
EasyReflection Lake Loop0.6 mi · 30 min · 3.8 mi awayAn easy loop for Lassen Peak reflected in the lake.
Sight · 1.9 mi awayDevastated AreaA short accessible loop through Lassen’s 1915 eruption story.
Scenic pullout · 2.2 mi awayHat Creek ViewpointA former lake is becoming meadow, still fed by spring water.
Campground · 2.3 mi awayLost Creek Group CampgroundEight reservable group sites under the ponderosa pines.
Campground · 2.5 mi awayVolcano Adventure CampCabins and ranger-led learning, reserved for youth groups.
Historic marker · 2.7 mi awaySunflower FlatA quick stop ties the park road to an 1850s wagon route.
Scenic pullout · 2.8 mi awayChaos Crags ViewpointQuick roadside stop: rock avalanches left a field of frozen waves.Sight · 3.3 mi awayParadise MeadowsA stream threads a high meadow beneath a rocky glacial bowl.
Sight · 3.3 mi awayLassen PeakA strenuous summit climb on one of the world’s largest plug domes.Parkwolf’s Lassen Volcanic ranking
The audio tour guide for the drive, plus offline maps, trails, and wildlife heatmaps for when the signal drops.
