LASSEN PEAK ALSO KNOWN AS MOUNT LASSEN ACTIVE VOLCANO THE CASCADE RANGE SHASTA CASCADE REGION NORTHERN CALIFORNIA LASSEN RISES ABOVE TERRAIN VOLUME LARGEST LAVA DOME NORTHEASTERN FLANK MOUNT TEHAMA STRATOVOLCANO HIGHER VOLCANIC ARC SOUTHWESTERN BRITISH COLUMBIA POWERFUL EXPLOSIVE ERUPTION DEVASTATED NEARBY SPREAD VOLCANIC ASH EXPLOSION ERUPTIONS MOUNT THE ONLY VOLCANOES CONTIGUOUS UNITED STATES ERUPT LASSEN VOLCANIC NATIONAL PARK SHASTA COUNTY PRESERVE AREAS FUTURE OBSERVATION VOLCANIC HIGHEST WINTER SNOWFALL IN CALIFORNIA AVERAGE ANNUAL SNOW FALLS ALTITUDE LAKE HELEN THE MOUNT AREA PRECIPITATION RAIN HAIL SNOW SOUTH THE THREE SISTERS HEAVY CREATES FOURTEEN PERMANENT PATCHES THE MOUNTAIN TOP RATHER MODEST GLACIER LIGHTNING STRIKE THE SUMMIT THE VOLCANO SUMMER THE CHAIN EIGHTEEN PEAKS STRETCH THE PAST MILLION YEARS JUAN DE FUCA TECTONIC PLATE SMALLER GORDA PLATE SUBDUCTED THE NORTH AMERICAN PLATE OCEANIC CRUST JUAN DE FUCA PLATE SUBDUCTION ZONE MAGMA UPLIFTED VOLCANIC ERUPTIONS YEARS AGO DACITE LAVA DOME PUSHED SHATTERED OVERLAYING BLANKET TALUS EMERGING CHAOS CRAGS REACHED PRESENT HEIGHT SHORT TIME PROBABLY THE LAST GLACIAL PERIOD THE CURRENT ICE AGE SHAPE GLACIAL EROSION DEPRESSION CIRQUE ERODED RECENT PERIOD LASTED SEVEN YEARS SENT STEAM TALL MUSHROOM ERUPTION THE EXPLOSION THE REGION REMAINS FUMAROLES HOT SPRINGS MOUNT SHASTA THE COMING DECADES CENTURIES THE ARRIVAL WHITE SETTLERS TRADITIONAL HOMELAND NORTHEASTERN MAIDU AMERICAN INDIAN HONOR THE DANISH BLACKSMITH PETER LASSEN IMMIGRANTS PAST PEAK SACRAMENTO VALLEY TRAIL NEVER GENERALIZED THE NOBLES EMIGRANT TRAIL WILLIAM NOBLES APPLEGATE TRAIL NORTHWESTERN NEVADA HELEN TANNER WHITE WOMAN REACH LAKE BEGINNING DORMANCY PHREATIC ERUPTION LAHAR WERE TO VOLCANIC ERUPTION ACTIVITY STARK CINDER CONE DESIGNATED ACTIVE SHAKEN STEAM EXPLOSION TOWARD THE SURFACE VOLCANO GROUND WATER SUPERHEATED WATER UNDER PRESSURE VENTS PATHS EXPLOSIONS WIDE CRATER CHARACTER CHANGED DRAMATICALLY EVENING INCANDESCENT BLOCKS LAVA SEEN DOWN FAR AWAY THE TOWN THE NEXT CONSISTING OF SILICA THE CRATER DACITE GLOWING HOT LAVA THE DOME FELL UPPER FALLING LAUNCHED HALF MILE AVALANCHE VOLCANIC ROCK STEEP NORTHEAST LOW RIDGE EMIGRANT PASS HAT CREEK BROKE THE SNOW MUDFLOW BULK HUGE VOLUMES FLOODING THE EARLY MORNING HOURS FLOOD RANCH HOUSES THE FEW PEOPLE HOUSES MINOR THE NIGHT OF SOMEWHAT FLUID THAT WHICH ON THE NIGHT SPOTS WEST QUIET DAYS THE GREAT EXPLOSION BLASTED ROCK PUMICE HIGH DEEPER COLUMN GAS ROSE VISIBLE EUREKA THE PACIFIC COAST ONTO SLOPE PYROCLASTIC FLOW THE SIDE WATER THE FLOW THE PATH NEARLY CREEK FLOODED AWAY THE NORTHEAST LOBE LAVA FLOW EXTRUDED TWO DAYS MUDFLOWS LAYER TRACEABLE FINE EVENTS DEVASTATED AREA POPULATED TREES NUTRIENT LEVEL POROSITY THE SOIL IN SPRING SNOWMELT TRIGGERED INDICATION BENEATH THE SURFACE THE NORTHWEST CORNER OLDER LOCATE THE UNITED STATES GEOLOGICAL SURVEY COOPERATION THE NATIONAL PARK SERVICE MONITORING GEOTHERMAL IN THE PARK FILM PUBLISHED SHASTA HISTORICAL CLIMBERS HIKERS THE MOUNTAIN POPULAR CLIMBING ROUTE MONTHS ROUND TRIP HIKE FEET TRAILHEAD ON THE MOUNTAIN INVOLVE LONGER ROAD CLOSURES EXTREME CONDITIONS THE PEAK HIGHEST POINTS COUNTY ULTRAS THE UNITED STATES