Lassen Volcanic National Park is an American national park in northeastern California. The dominant feature of the park is Lassen Peak, the largest plug dome volcano in the world and the southernmost volcano in the Cascade Range. Lassen Volcanic National Park is one of the few areas in the world where all four types of volcano can be found—plug dome, shield, cinder cone, and stratovolcano.
The Lassen volcanic area presents a geological record of sedimentation and volcanic activity in and around Lassen Volcanic National Park in Northern California, U.S. The park is located in the southernmost part of the Cascade Mountain Range in the Pacific Northwest region of the United States. Pacific Oceanic tectonic plates have plunged below the North American Plate in this part of North America for hundreds of millions of years. Heat and molten rock from these subducting plates has fed scores of volcanoes in California, Oregon, Washington and British Columbia over at least the past 30 million years, including these in the Lassen volcanic areas.
Lassen Peak, commonly referred to as Mount Lassen, is the southernmost active volcano in the Cascade Range of the Western United States. Located in the Shasta Cascade region of Northern California, it is part of the Cascade Volcanic Arc, which stretches from southwestern British Columbia to northern California. Lassen Peak reaches an elevation of 10,457 ft (3,187 m), standing above the northern Sacramento Valley. It supports many flora and fauna among its diverse habitats, which are subject to frequent snowfall and reach high elevations.
The geothermal areas in Lassen Volcanic National Park include several groups of hot springs and fumaroles, as remnants of former volcanic activity, exist in Lassen Volcanic National Park in northeastern California. Most of these lie in or are closely adjacent to Mount Tehama's caldera. Bumpass Hell is the most spectacular of these, but others of importance are Sulphur Works, Little Hot Springs Valley, Boiling Springs Lake and Devil's Kitchen. In each thermal area, the highest temperature of water generally is close to the boiling temperature at the altitude of the particular spring or fumarole — 198 °F (92 °C) at Bumpass Hell and 191 °F (88 °C) on the northwest flanks of Lassen Peak. Temperatures as high as 230 °F (110 °C) have been recorded in the park.
Chaos Crags is the youngest group of lava domes in Lassen Volcanic National Park, California. They formed as six dacite domes 1,100-1,000 years ago, one dome collapsing during an explosive eruption about 70 years later. The eruptions at the Chaos Crags mark one of just three instances of Holocene activity within the Lassen volcanic center. The cluster of domes is located north of Lassen Peak and form part of the southernmost segment of the Cascade Range in Northern California. Each year, a lake forms at the base of the Crags, and typically dries by the end of the summer season.
Cinder Cone is a cinder cone volcano in Lassen Volcanic National Park within the United States. It is located about 10 mi (16 km) northeast of Lassen Peak and provides an excellent view of Brokeoff Mountain, Lassen Peak, and Chaos Crags.
Mount Tehama is an eroded andesitic stratovolcano in the Cascade Volcanic Arc and the Cascade Range in Northern California. Part of the Lassen volcanic area, its tallest remnant, Brokeoff Mountain, is itself the second highest peak in Lassen Volcanic National Park and connects to the park's highest point, Lassen Peak. Located on the border of Tehama County and Shasta County, Brokeoff's peak is the highest point in the former. The hikers that summit this mountain each year are treated to "exceptional" views of Lassen Peak, the Central Valley of California, and many of the park's other features. On clear days, Mount Shasta can also be seen in the distance.
Lassen National Forest is a United States national forest of 1,700 square miles (4,300 km2) in northeastern California. It is named after pioneer Peter Lassen, who mined, ranched and promoted the area to emigrant parties in the 1850s.
State Route 89 is a state highway in the U.S. state of California that travels in the north–south direction, serving as a major thoroughfare for many mountain communities in the Sierra Nevada and the Cascade Range. It starts from U.S. Route 395 near Topaz Lake, winding its way up to the 8,314-foot (2,534 m) Monitor Pass, down to the Carson River, and up again over the 7,740-foot (2,359 m) Luther Pass. From that point on, the route generally loses elevation on its way past Lake Tahoe, through Tahoe and Plumas National Forests until Lake Almanor. For roughly nine miles the route is then a part of State Route 36. The route then ascends to the 5,753-foot (1,754 m) Morgan Summit. After it enters Lassen Volcanic National Park it continues to gain elevation until it reaches its highest point in an unnamed pass in the middle of Lassen Peak and Bumpass Mountain. The road then descends and heads northwest, finally terminating at Interstate 5 at the foot of Mount Shasta at around 3,600 feet (1,100 m).
Hat Creek is a 48.7-mile-long (78.4 km) stream and tributary of the Pit River, located in Shasta County of northern California.
Lake Helen is a glacial lake or a tarn occupying a cirque at around 8,200 feet in Lassen Volcanic National Park. The lake is located to the south of Lassen Peak and west of Bumpass Mountain in the Shasta Cascades region of Northern California. Highway 89 runs along the lake's southern and eastern shore. The lake is named for Helen Tanner Brodt who in 1864 became the first white woman to reach the summit of Lassen Peak.
The Thousand Lakes Wilderness is located within the southern portion of the Cascade Range in northeastern California. The 16,335-acre (66 km2) wilderness was established in 1964 with the passage of the Wilderness Act and is administered by Lassen National Forest. The area lies within Shasta County, midway between the town of Burney and Lassen Volcanic National Park.
Summit Lake is a lake in the Lassen Volcanic National Park of Shasta County, California, east of California Route 89 at elevation 6,700 ft (2,000 m). Two campgrounds, named Summit Lake North and Summit Lake South, are located adjacent to the lake.
Juniper Lake is a large lake located at the southeast corner of Lassen Volcanic National Park in the U.S. state of California. The lake sits at an elevation of 6,700 ft (2,040 m) above sea level. There is a campground and a ranger station located on the eastern shore of the lake, and a campground and private cabins located on the northern shore. The lake is accessible by an unpaved road from Chester.
Snag Lake is a lake located in the north eastern part of Lassen Volcanic National Park in California.
Horseshoe Lake is a lake located in the eastern part of Lassen Volcanic National Park near Juniper Lake, in Shasta County, California. The lake lies at an elevation of 6,550 ft (1,996 m). Water from Horseshoe Lake drains to Snag Lake via Grassy Creek. The lake is accessible by hiking trail only.
Bumpass Mountain is a mountain located south of Lassen Peak in Lassen Volcanic National Park, California. It rises to an elevation of 8,753 feet (2,668 m) near Bumpass Hell and Lake Helen. The mountain receives heavy snowfall during the winter, which can lead to deep snowpacks of over 300 inches near the mountain.
Morgan Summit is a mountain pass on a road shared by Highway 89 and Highway 36 in Tehama County, California. The pass is located in between the town of Mineral and Childs Meadow south of Lassen Peak and Lassen Volcanic National Park. The stated elevation of the pass varies between 5,753 ft (1,754 m) and 5,768 ft (1,758 m). The pass is high enough to receive snowfall during the winter.
Indian Creek is a major stream in the northern Sierra Nevada of Plumas County, California and is part of the Feather River system. The creek is 47 miles (76 km) long, flowing through a series of small towns and farming valleys in a rural, mountainous area.
