Lassen Volcanic National Park is a national park of the United States 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 volcanoes can be found: plug dome, shield, cinder cone, and stratovolcano.
The source of heat for the volcanism in the Lassen area is subduction of the Gorda plate diving below the North American plate off the Northern California coast. The area surrounding Lassen Peak is still active with boiling mud pots, fumaroles, and hot springs.
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. Chapter 8: The Proclamation of National Monuments Under the Antiquities Act, 1906–1970 Starting in May 1914 and lasting until 1917, a series of minor to major eruptions occurred on Lassen. Because of the eruptive activity and the area's stark volcanic beauty, Lassen Peak, Cinder Cone, and the area surrounding were established as a National Park on August 9, 1916.
History The Atsugewi have inhabited the area since long before white settlers first saw Lassen. They knew that the peak was full of fire and water and thought it would one day blow itself apart.Geology of National Parks, pp. 542–46.
European immigrants in the mid-19th century used Lassen Peak as a landmark on their trek to the fertile Sacramento Valley. One of the guides to these immigrants was a Danish blacksmith named Peter Lassen, who settled in Northern California in the 1830s. Lassen Peak was named after him. Nobles Emigrant Trail was later cut through the park area and passed Cinder Cone and the Fantastic Lava Beds.
Inconsistent newspaper accounts reported by witnesses from 1850 to 1851 described seeing "fire thrown to a terrible height" and "burning lava running down the sides" in the area of Cinder Cone. As late as 1859, a witness reported seeing fire in the sky from a distance, attributing it to an eruption. Early geologists and volcanologists who studied the Cinder Cone concluded the last eruption occurred between 1675 and 1700. After the 1980 eruption of Mount St. Helens, the United States Geological Survey (USGS) began reassessing the potential risk of other active volcanic areas in the Cascade Range. Further study of Cinder Cone estimated the last eruption occurred between 1630 and 1670. Recent tree-ring analysis has placed the date at 1666.
The Lassen area was first protected by being designated as the Lassen Peak Forest Preserve. Lassen Peak and Cinder Cone were later declared as U.S. National Monuments in May 1907 by President Theodore Roosevelt.Geology of U.S. Parklands, p. 154.
Starting in May 1914 and lasting until 1921, a series of minor to major eruptions occurred on Lassen. These events created a new crater, and released lava and a great deal of ash. Fortunately, because of warnings, no one was killed, but several houses along area creeks were destroyed. Because of the eruptive activity, which continued through 1917, and the area's stark volcanic beauty, Lassen Peak, Cinder Cone and the area surrounding were declared a National Park on August 9, 1916.
The Main Park Road was constructed between 1925 and 1931, just 10 years after Lassen Peak erupted. Near Lassen Peak the road reaches , making it the highest road in the Cascade Mountains. It is not unusual for of snow to accumulate on the road near Lake Helen and for patches of snow to last into July.
In October 1972, a portion of the park was designated as Lassen Volcanic Wilderness by the US Congress (Public Law 92-511). The National Park Service seeks to manage the wilderness in keeping with the Wilderness Act of 1964, with minimal developed facilities, signage, and trails. The management plan of 2003 adds that, "The wilderness experience offers a moderate to high degree of challenge and adventure."
In 1974, the National Park Service took the advice of the USGS and closed the visitor center and accommodations at Manzanita Lake. The Survey stated that these buildings would be in the way of a rockslide from Chaos Crags if an earthquake or eruption occurred in the area. An aging seismograph station remains. However, a campground, store, and museum dedicated to Benjamin F. Loomis stands near Manzanita Lake, welcoming visitors who enter the park from the northwest entrance.
After the Mount St. Helens eruption, the USGS intensified its monitoring of active and potentially active volcanoes in the Cascade Range. Monitoring of the Lassen area includes periodic measurements of ground deformation and volcanic-gas emissions and continuous transmission of data from a local network of nine seismometers to USGS offices in Menlo Park, California.USGS: Volcano Hazards of the Lassen Volcanic National Park Area, California Should indications of a significant increase in volcanic activity be detected, the USGS will immediately deploy scientists and specially designed portable monitoring instruments to evaluate the threat. In addition, the National Park Service (NPS) has developed an emergency response plan that would be activated to protect the public in the event of an impending eruption.
A downhill skiing site operating in the area was closed in 1992. The last remaining part was the Lassen Chalet, located near the southwest entrance, which was finally demolished in 2005. The new Kohm Yah-mah-nee Visitor Center opened to the public at the same location in 2008. It was so named after the Mountain Maidu name for Lassen Peak.
In 2021, the Dixie Fire burned large portions of the National Park, becoming the largest wildfire in park history. On August 5, 2021, the fire entered Lassen Volcanic National Park near Juniper Lake and the entire park was closed for safety. The town of Mineral, including park headquarters, was forced to evacuate. Structure loss occurred at the Drakesbad Guest Ranch and at cabins near Juniper Lake. The Dixie Fire's advance northward was slowed by the 2012 Reading Fire footprint, but the Dixie Fire ultimately burned 73,240 acres within the park—approximately 69% of the park's total area. 12,845 acres, or 18% of that area, burned at a severity that left the landscape unchanged. 34,450 acres, or 49% of the burned area in the park, burned at a low-to-moderate severity. The remaining 23,493 acres, or 33% of the area burned by the Dixie Fire in Lassen Volcanic National Park, burned at a high severity.
Visitation
The NPS tracks visitors to Lassen by using in-road inductive loops at all vehicle entrances which count passing vehicles. Buses and other non-reportable vehicles are subtracted from the vehicle count, which is then multiplied by three, an estimate of the number of visitors per vehicle.
Visitation By Year Year Recreational visitors 2000 374,911 2001 376,695 2002 388,149 2003 404,384 2004 379,667 2005 365,535 2006 388,741 2007 395,057 2008 377,361 2009 365,639 2010 384,570 2011 351,269 2012 407,653 2013 427,409 2014 432,977 2015 468,092 2016 536,068 2017 507,256 2018 499,435 2019 517,039 2020 542,274 2021 359,6352022446,2912023418,9782024357,6512025407,653
Geography and geology
The park is located near the northern end of the Sacramento Valley, near the cities of Redding and Susanville. It is located in portions of Shasta, Lassen, Plumas, and Tehama counties.
The western part of the park features great lava pinnacles (huge mountains created by lava flows), jagged craters, and steaming sulfur vents. It is cut by glaciated canyons and is dotted and threaded by lakes and rushing clear streams.
The eastern part of the park is a vast lava plateau more than one mile (1.6 km) above sea level. Here, small cinder cones are found (Fairfield Peak, Hat Mountain, and Crater Butte). Forested with pine and fir, this area is studded with small lakes, but it boasts few streams. Warner Valley, marking the southern edge of the Lassen Plateau, features hot spring areas (Boiling Springs Lake, Devils Kitchen, and Terminal Geyser). This forested, steep valley also has large meadows that have wildflowers in spring.
Lassen Peak is made of dacite, an igneous rock, and is the world's largest plug dome volcano. It is also the southernmost non-extinct volcano of the Cascade Range (specifically, the Shasta Cascade part of the range). The tall volcano sits on the north-east flank of the remains of Mount Tehama, a stratovolcano that was a thousand feet (305 m) higher than Lassen and wide at its base. After emptying its throat and partially doing the same to its magma chamber in a series of eruptions, Tehama either collapsed into itself and formed a two-mile (3.2 km) wide caldera in the late Pleistocene or was simply eroded away with the help of acidic vapors that loosened and broke the rock, which was later carried away by glaciers.
Sulphur Works is a geothermal area in between Lassen Peak and Brokeoff Mountain that is thought to mark an area near the center of Tehama's now-gone cone. Other geothermal areas in the caldera are Little Hot Springs Valley, Diamond Point (an old lava conduit), and Bumpass Hell (see Geothermal areas in Lassen Volcanic National Park).
The magma that fuels the volcanoes in the park is derived from subduction off the coast of Northern California. Cinder Cone and the Fantastic Lava Beds, located about northeast of Lassen Peak, is a cinder cone volcano and associated lava flow field that last erupted about 1650. It created a series of basaltic andesite to andesite lava flows known as the Fantastic Lava Beds.
There are four shield volcanoes in the park; Mount Harkness (southwest corner of the park), Red Mountain (at south-central boundary), Prospect Peak (in northeast corner), and Raker Peak (north of Lassen Peak). All of these volcanoes are 7,000–8,400 feet (2,133–2,560 m) above sea level and each is topped by a cinder cone volcano.
During ice ages, glaciers have modified and helped to erode the older volcanoes in the park. The center of snow accumulation and therefore ice radiation was Lassen Peak, Red Mountain, and Raker Peak. These volcanoes thus show more glacial scarring than other volcanoes in the park.
Despite not having any glaciers currently, Lassen Peak does have 14 permanent snowfields.
Access The park is accessible via State Routes 89 and 44. SR 89 passes north–south through the park, beginning at SR 36 to the south and ending at SR 44 to the north. SR 89 passes immediately adjacent to the base of Lassen Peak. There are five vehicle entrances to the park: the north and south entrances on SR 89; and unpaved roads entering at Drakesbad and Juniper Lake in the south, and at Butte Lake in the northeast. The park can also be accessed by trails leading in from the Caribou Wilderness to the east, as well as the Pacific Crest Trail, and two smaller trails leading in from Willow Lake and Little Willow Lake to the south.
The segment of SR 89 through the park is typically closed during the winter due to very heavy snowfall and snowpack.
Climate
According to the Köppen climate classification system, Lassen Volcanic National Park has a Mediterranean-influenced warm-summer Humid continental climate (Dsb). According to the United States Department of Agriculture, the Plant Hardiness zone at Kohm Yah-mah-nee Visitor Center at elevation is 6b with an average annual extreme minimum temperature of .