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 started as two separate national monuments designated by President Theodore Roosevelt in 1907: Cinder Cone National Monument and Lassen Peak National Monument.
The geology of the Lassen volcanic area presents a record of sedimentation and volcanic activity in the area 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 from these subducting plates has fed scores of volcanoes in California, Oregon, Washington and British Columbia over at least the past 30 million years and is also responsible for activities in the Lassen volcanic area.
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 feet (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.
Mount Jefferson is a stratovolcano in the Cascade Volcanic Arc, part of the Cascade Range in the U.S. state of Oregon. The second highest mountain in Oregon, it is situated within Linn County, Jefferson County, and Marion County and forms part of the Mount Jefferson Wilderness. Due to the ruggedness of its surroundings, the mountain is one of the hardest volcanoes to reach in the Cascades. It is also a popular tourist destination despite its remoteness, with recreational activities including hiking, backpacking, mountaineering, and photography. Vegetation at Mount Jefferson is dominated by Douglas fir, silver fir, mountain hemlock, ponderosa pine, lodgepole pine, and several cedar species. Carnivores, insectivores, bats, rodents, deer, birds, and various other species inhabit the area.
Mount Thielsen, or Big Cowhorn, is an extinct shield volcano in the Oregon High Cascades, near Mount Bailey. Because eruptive activity ceased 250,000 years ago, glaciers have heavily eroded the volcano's structure, creating precipitous slopes and a horn-like peak. The spire-like shape of Thielsen attracts lightning strikes and creates fulgurite, an unusual mineral. The prominent horn forms a centerpiece for the Mount Thielsen Wilderness, a reserve for recreational activities such as skiing and hiking.
Three Fingered Jack is a summit of a shield volcano of the Cascade Range in the U.S. state of Oregon. Formed during the Pleistocene epoch, the mountain consists mainly of basaltic andesite lava and was heavily glaciated in the past. While other Oregon volcanoes that were heavily glaciated—such as Mount Washington and Mount Thielsen—display eroded volcanic necks, Three Fingered Jack's present summit is a comparatively narrow ridge of loose tephra supported by a dike only 10 feet (3.0 m) thick on a generally north–south axis. Radiating dikes and plugs that support this summit have been exposed by glaciation. The volcano has long been inactive and has been highly eroded.
Mount Washington is a deeply eroded volcano in the Cascade Range of Oregon. It lies within Deschutes and Linn counties and is surrounded by the Mount Washington Wilderness area.
Mount McLoughlin is a dormant steep-sided stratovolcano, or composite volcano, in the Cascade Range of southern Oregon and within the Sky Lakes Wilderness. It is one of the volcanic peaks in the Cascade Volcanic Arc, within the High Cascades sector. A prominent landmark for the Rogue River Valley, the mountain is north of Mount Shasta, and Crater Lake lies to the north-northeast. It was named around 1838 after John McLoughlin, a Chief Factor for the Hudson's Bay Company. Mount McLouglin's prominence has made it a landmark to Native American populations for thousands of years.
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 highest remaining 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.
Goat Rocks is an extinct stratovolcano in the Cascade Range, located between Mount Rainier and Mount Adams in southern Washington, in the United States. Part of the Cascade Volcanoes, it was formed by the subduction of the Juan de Fuca Plate under the western edge of the North American Plate. The volcano was active from 3.2 million years ago until eruptions ceased between 1 and 0.5 million years ago. Throughout its complex eruptive history, volcanism shifted from silicic explosive eruptions to voluminous, mafic activity.
The Three Sisters are closely spaced volcanic peaks in the U.S. state of Oregon. They are part of the Cascade Volcanic Arc, a segment of the Cascade Range in western North America extending from southern British Columbia through Washington and Oregon to Northern California. Each more than 10,000 feet (3,000 m) in elevation, they are the third-, fourth- and fifth-highest peaks in Oregon. Located in the Three Sisters Wilderness at the boundary of Lane and Deschutes counties and the Willamette and Deschutes national forests, they are about 10 miles (16 km) south of the nearest town, Sisters. Diverse species of flora and fauna inhabit the area, which is subject to frequent snowfall, occasional rain, and extreme temperature variation between seasons. The mountains, particularly South Sister, are popular destinations for climbing and scrambling.
The Milbanke Sound Group, also called the Milbanke Sound Cones, is an enigmatic group of five small basaltic volcanoes in the Kitimat Ranges of the Coast Mountains in British Columbia, Canada. Named for Milbanke Sound, this volcanic group straddles on at least four small islands, including Swindle, Price, Lady Douglas and Lake Island. Not much is known about this group of volcanoes and they remain undated. However, they all likely formed in the past 10,000 years after the last glacial period as evidenced by a small amount of erosion. The age of the most recent volcanic activity is also unknown. Most of the Milbanke Sound Cones are covered by mature forest. Kitasu Hill and Helmet Peak are the only two cones that are officially named.
Diamond Peak is a volcano in Klamath and Lane counties of central Oregon in the United States. It is a shield volcano, though it might also be considered a modest stratocone. Diamond Peak forms part of the Cascade Volcanic Arc, a segment of the Cascade Range in western North America extending from southern British Columbia through Oregon to Northern California. Reaching an elevation of 8,748 feet (2,666 m), the mountain is located near Willamette Pass in the Diamond Peak Wilderness within the Deschutes and Willamette national forests. Surrounded by coniferous forest and visible in the skyline from foothills near Eugene, Diamond Peak offers a few climbing routes and can be scrambled.
Level Mountain is a massive complex volcano in the Northern Interior of British Columbia, Canada. It is located 50 km (31 mi) north-northwest of Telegraph Creek and 60 km (37 mi) west of Dease Lake on the Nahlin Plateau. With a maximum elevation of 2,166 m (7,106 ft), it is the third highest of five large complexes in an extensive north-south trending volcanic zone. Much of the mountain is gently-sloping; when measured from its base, Level Mountain is about 1,100 m (3,600 ft) tall, slightly taller than its neighbour to the northwest, Heart Peaks. The lower broader half of Level Mountain consists of a shield-like edifice while its upper half has a more steep, jagged profile. Its large summit is dominated by the Level Mountain Range, a small mountain range with prominent peaks cut by deep valleys. These valleys serve as a radial drainage for several small streams that flow from the volcano. Meszah Peak is the only named peak in the Level Mountain Range.
West Crater is a small lava dome with associated lava flows in southern Washington, United States. Located in Skamania County, it rises to an elevation of 4,131 feet (1,259 m), and forms part of the Cascade Volcanic Arc. It is also part of the Marble Mountain-Trout Creek Hill volcanic field, a little-known Quaternary volcanic field in the southern Cascades of Washington state. The area can be hiked, and can be accessed by roads in the Gifford Pinchot National Forest.
The geology of the Pacific Northwest includes the composition, structure, physical properties and the processes that shape the Pacific Northwest region of North America. The region is part of the Ring of Fire: the subduction of the Pacific and Farallon Plates under the North American Plate is responsible for many of the area's scenic features as well as some of its hazards, such as volcanoes, earthquakes, and landslides.
The Raton-Clayton volcanic field is a volcanic field located in the state of New Mexico, United States. Capulin Volcano National Monument is located in the volcanic field. It is the northeasternmost volcanic field of the Jemez Lineament and the easternmost Cenozoic volcanic field of North America.
The Wells Gray-Clearwater volcanic field, also called the Clearwater Cone Group, is a potentially active monogenetic volcanic field in east-central British Columbia, Canada, located approximately 130 km (81 mi) north of Kamloops. It is situated in the Cariboo Mountains of the Columbia Mountains and on the Quesnel and Shuswap Highlands. As a monogenetic volcanic field, it is a place with numerous small basaltic volcanoes and extensive lava flows.
The Mount Edziza volcanic complex is a large and potentially active north-south trending complex volcano in Stikine Country, northwestern British Columbia, Canada, located 38 kilometres (24 mi) southeast of the small community of Telegraph Creek. It occupies the southeastern portion of the Tahltan Highland, an upland area of plateau and lower mountain ranges, lying east of the Boundary Ranges and south of the Inklin River, which is the east fork of the Taku River. As a volcanic complex, it consists of many types of volcanoes, including shield volcanoes, calderas, lava domes, stratovolcanoes, and cinder cones.
Round Top is a 10,381-foot (3,164 m) mountain located on the Sierra crest in Alpine County, California. Its summit is the highest point in Eldorado National Forest and the Mokelumne Wilderness. The mountain lies just south of Carson Pass. With 2,541 feet (774 m) of prominence, Round Top is the 16th most prominent mountain in the Sierra Nevada.
