Lassen Volcanic National Park

Lassen Volcanic National Park covers 106,589 acres in northeastern California at the southern end of the Cascade Range, roughly 50 miles east of Redding and about 250 miles north of San Francisco. The park is one of the few places in the world where all four types of volcanoes, plug dome, shield, cinder cone, and composite stratovolcano, appear within a single park boundary. A 29-mile park highway crosses the park from the northwest entrance near Manzanita Lake to the southwest entrance near Mineral, giving road access to major hydrothermal features, trailheads, and lake viewpoints. The park draws about 516,000 visitors per year, ranking 46th among the 63 national parks, with visitation concentrated in summer when the highway is snow-free.

Lassen Peak, the world's largest plug dome volcano at 10,457 feet, which last erupted in a series of events from 1914 to 1921 and whose May 22, 1915 explosion sent an ash column 30,000 feet into the air and created the Devastated Area still visible along the park highway.
Bumpass Hell, a 3-acre hydrothermal basin reached by a 3-mile round-trip trail, containing the highest concentration of boiling mudpots, fumaroles, and acid sulfate pools in the park, with water temperatures at some vents reaching 322 degrees Fahrenheit.
The presence of all four volcano types: Lassen Peak is a plug dome, Prospect Peak and Raker Peak are shield volcanoes, Cinder Cone in the northeast corner is a classic cinder cone, and Brokeoff Mountain is a remnant of ancient Mount Tehama, a composite stratovolcano.
The 29-mile park highway, open roughly mid-June through November depending on snowpack, which connects a chain of trailheads, hydrothermal overlooks, and mountain lakes including Manzanita, Summit, and Emerald.

Northwest entrance (main entrance): From Redding, take Highway 44 east approximately 45 miles to the junction with SR-89 south at the park boundary. This entrance is the most direct from Redding and Sacramento and provides the fastest access to Manzanita Lake, the visitor center, and the northern half of the park highway. Driving time from Redding is about 1 hour.

Southwest entrance: From Interstate 5 at Red Bluff, take Highway 36 east approximately 60 miles to the SR-89 junction near Mineral, then north on SR-89 to the southwest entrance. This entrance is closest to Bumpass Hell, Brokeoff Mountain, and Sulphur Works. Driving time from Red Bluff is about 90 minutes.

From Sacramento: Drive north on I-5 approximately 130 miles to Red Bluff, then take Highway 36 east to the southwest entrance, or continue on I-5 to Highway 44 east for the northwest entrance. Total driving time from Sacramento is about 3 hours depending on route. There is no direct public transit to the park.

By air: Redding Municipal Airport (RDD) is the closest option, roughly 50 miles from the northwest entrance, with daily commuter flights from San Francisco and Los Angeles. Sacramento International Airport (SMF), roughly 170 miles from the southwest entrance, offers nonstop service from most major U.S. cities and is a common gateway for visitors combining Lassen with other northern California destinations.

Lassen Volcanic sits on the southern end of the Cascade Range, where the Pacific Plate subducts beneath North America and drives ongoing volcanism from British Columbia through northern California. The park contains all four recognized volcano types because it straddles the intersection of the Cascade arc and the Basin and Range extensional province, each of which favors different eruption styles. Lassen Peak itself is the largest plug dome volcano in the world, formed when thick, gas-poor lava was pushed upward without erupting explosively, building a steep-sided dome of dacite rock over roughly 27,000 years.

The broader landscape is built on the ruins of ancient Mount Tehama, a composite stratovolcano that stood about 11,500 feet and was active roughly 600,000 to 400,000 years ago. After Tehama's magma supply waned, the structure collapsed inward and glaciers carved the caldera into the broad valley visible from Brokeoff Mountain today. Brokeoff Mountain, Pilot Pinnacle, and Mount Diller are the surviving remnants of Tehama's rim. Hydrothermal waters from a still-active magma body beneath the surface heat the remnant plumbing, driving the boiling pools and fumaroles at Bumpass Hell, Sulphur Works, Devils Kitchen, and Boiling Springs Lake.

Cinder Cone in the northeast corner of the park represents a completely different eruptive style: basaltic lava erupted explosively, piling cinders into a symmetrical 700-foot cone. Eruptions occurred around 1650 and again around 1666, producing the Painted Dunes, where oxidized ash coats the lava field in vivid red and orange. Chaos Crags, a cluster of dacite lava domes near the northwest entrance, formed about 1,000 years ago; around 300 years ago, one flank of the crags collapsed in a large avalanche that created the Chaos Jumbles deposit, still visible as a hummocky rock field below the crags.

Lassen Peak erupted 150 to 300 times from May 1914 through June 1917, with the largest explosion on May 22, 1915. That eruption sent volcanic debris and a lahar down the mountain's northeast flank, knocking down and burying trees across a wide area now called the Devastated Area. The blast cloud deposited ash as far as 280 miles to the east. Recovery vegetation has returned across most of the Devastated Area, but bleached snag stumps and young forest stand as a record of the eruption that prompted Congress to create the park the following year.

Black bears live throughout the park's forested zones and are most commonly encountered near the campgrounds and along the park highway in early morning and evening. Lassen's bears are habituated to food odors and the park enforces strict food storage rules; all food and scented items must be stored in a bear box or hard-sided container when not actively in use. Mule deer graze the meadows at Kings Creek and near Summit Lake at dawn and dusk. Pika, the small rounded relatives of rabbits, inhabit rocky talus slopes on Lassen Peak and Brokeoff Mountain and are heard more often than seen.

Manzanita Lake supports beavers whose lodges and dams are visible from the lake loop trail. Ospreys and bald eagles fish the larger park lakes in summer. The black-backed woodpecker, a specialist species that depends on fire-killed snags, is found in the burned zones within and adjacent to the park and is sought by birders. Clark's nutcracker is common at higher elevations, where it caches whitebark pine seeds in the rocky terrain above treeline.

Pacific chorus frogs and the Sierra Nevada yellow-legged frog inhabit the meadow streams and lake margins. The yellow-legged frog has declined significantly across the Sierra Nevada due to introduced trout and disease; Lassen is one of the parks where recovery efforts are ongoing. Cascades frogs are common in the subalpine wetlands near Summit Lake. Black-tailed jackrabbits appear in the lower-elevation chaparral zones near the southwest entrance.

The Atsugewi, Yana, Maidu, and Yahi peoples have lived in and around the Lassen region for thousands of years, using the mountain flanks for hunting, gathering, and seasonal travel between the valley floor and high elevations. The volcanic landscape held spiritual significance, and hot spring areas were known and used by Indigenous groups long before European contact. The Yahi, a subgroup of the Yana, maintained a hidden existence in the rough terrain southeast of the park into the early 20th century; in 1911, Ishi, the last known Yahi, was found near Oroville and brought to the University of California at Berkeley, where he lived until his death in 1916.

Peter Lassen, a Danish-American blacksmith and trapper, used the peak as a landmark while guiding emigrant wagon parties north of the Sierra Nevada in the 1830s and 1840s. He named the peak after himself on an 1846 map, and the name stuck. The mountain attracted scientific and recreational attention after the California Gold Rush brought settlers to the region; early climbs were recorded in the 1850s. The U.S. Geological Survey mapped the volcanic features extensively in the late 19th century.

Lassen Peak began erupting on May 30, 1914, surprising residents of the surrounding towns. Over the following year the eruptions intensified, culminating in the Great Hot Blast of May 22, 1915, which produced a lateral blast of hot volcanic debris and a lahar that traveled several miles down the northeast flank. The eruption was widely photographed and drew national attention to the volcanic hazard and the remarkable landscape. President Woodrow Wilson signed legislation creating Lassen Volcanic National Park on August 9, 1916, the same day he signed bills creating Hawaii Volcanoes National Park and Mount McKinley (now Denali) National Park.

Activity at Lassen continued at low levels through 1921 before quieting. The Loomis Museum near the northwest entrance, built in 1927 and named for Benjamin F. Loomis whose photographs documented the 1914 to 1917 eruptions, displays the original photographic record of the eruption sequence and remains the primary historical interpretive site in the park.