Mount Shasta

This article is about the volcano in California. For the town, see Mount Shasta, California. For other peaks named Shasta, see List of peaks named Shasta.

Mount Shasta
Aerial view of Mount Shasta from the west
Highest point
Elevation	14,179 ft (4321.8 m)  NAVD88
Prominence	9772 ft (2979 m)
Isolation	335 mi (539 km)
Parent peak	North Palisade
Listing	Ultra prominent peak California fourteener California county high point
Coordinates
Geography
Location	Siskiyou County, California, U.S.
Parent range	Cascade Range
Topo map	USGS Mount Shasta
Geology
Age of rock	About 593,000 years
Mountain type	Stratovolcano
Volcanic arc	Cascade Volcanic Arc
Last eruption	1786
Climbing
First ascent	1854 by E. D. Pearce and party
Easiest route	Avalanche Gulch ("John Muir") route: talus/snow climb
U.S. National Natural Landmark
Designated	1976

Mount Shasta (Karuk: Úytaahkoo or "White Mountain") is a potentially active volcano located at the southern end of the Cascade Range in Siskiyou County, California. At an elevation of 14,179 feet (4321.8 m), it is the second highest peak in the Cascades and the fifth highest in California. Mount Shasta has an estimated volume of 85 cubic miles (350 km³) which makes it the most voluminous stratovolcano in the Cascade Volcanic Arc.

The mountain and its surrounding area are managed by the U.S. Forest Service, Shasta-Trinity National Forest.

Description

Mount Shasta is connected to nearby Mt. Shastina and they dominate the northern California landscape. It rises abruptly and stands nearly 10,000 ft (3,000 m) above the surrounding terrain. On a clear winter day snowy Mount Shasta can be seen from the floor of the Central Valley 140 miles (230 km) south. The mountain has attracted the attention of poets, authors, and presidents.

The mountain consists of four overlapping volcanic cones which have built a complex shape, including the main summit and the prominent satellite cone of 12,330 ft (3,760 m) Shastina, which has a visibly conical form. If Shastina were a separate mountain, it would rank as the fourth-highest peak of the Cascade Range (after Mount Rainier, Rainier's Liberty Cap, and Mount Shasta itself).

Mount Shasta's surface is relatively free of deep glacial erosion except, paradoxically, for its south side where Sargents Ridge runs parallel to the U-shaped Avalanche Gulch. This is the largest glacial valley on the volcano, although it does not presently have a glacier in it. There are seven named glaciers on Mount Shasta, with the four largest (Whitney, Bolam, Hotlum, and Wintun) radiating down from high on the main summit cone to below 10,000 ft (3,000 m) primarily on the north and east sides. The Whitney Glacier is the longest and the Hotlum is the most voluminous glacier in the state of California. Three of the smaller named glaciers occupy cirques near and above 11,000 ft (3,400 m) on the south and southeast sides, including the Watkins, Konwakiton, and Mud Creek Glaciers.

History

The oldest known human habitation in the area dates to about 7,000 years ago, and by about 5,000 years ago, there was substantial human habitation in the surrounding area.

At the time of Euro-American contact in the 1820s, the Native American tribes who lived within view of Mount Shasta included the Shasta, Okwanuchu, Modoc, Achomawi, Atsugewi, Karuk, Klamath, Wintu, and Yana tribes.

The historic eruption of Mount Shasta in 1786 may have been observed by Lapérouse, but this is disputed. Although perhaps first seen by Spanish explorers, the first reliably reported land sighting of Mount Shasta by a European or American was by Peter Skene Ogden (a leader of a Hudson's Bay Company trapping brigade) in 1826. In 1827, the name "Sasty" or "Sastise" was given to nearby Mount McLoughlin by Ogden. The name was transferred to present-day Mount Shasta in 1841, partly as a result of work by the United States Exploring Expedition.

Mount Shasta seen from a small farm south of Weed, California.

Beginning in the 1820s, Mount Shasta was a prominent landmark along what became known as the Siskiyou Trail, which runs at Mount Shasta's base. The Siskiyou Trail was located on the track of an ancient trade and travel route of Native American footpaths between California's Central Valley and the Pacific Northwest.

The California Gold Rush brought the first Euro-American settlements into the area in the early 1850s, including at Yreka, California and Upper Soda Springs. The first recorded ascent of Mount Shasta occurred in 1854 (by Elias Pearce), after several earlier failed attempts. In 1856, the first women (Harriette Eddy, Mary Campbell McCloud, and their party) reached the summit.

Clarence King exploring the Whitney Glacier in 1870. This was the first glacier in the continental United States discovered and named. It was named for Josiah Whitney, head of the California Geological Survey.

By the 1860s and 1870s, Mount Shasta was the subject of scientific and literary interest. A book by California pioneer and entrepreneur James Hutchings, titled Scenes of Wonder and Curiosity in California, contained an account of an early summit trip in 1855. The summit was achieved (or nearly achieved) by John Muir, Josiah Whitney, Clarence King, and John Wesley Powell. In 1877, Muir wrote a dramatic popular article about an experience in which he survived an overnight blizzard on Mount Shasta by lying in the hot sulfur springs found near the summit.

The 1887 completion of the Central Pacific Railroad, built along the line of the Siskiyou Trail between California and Oregon, brought a substantial increase in tourism, lumbering, and population into the area around Mount Shasta. Early resorts and hotels, such as Shasta Springs and Upper Soda Springs, grew up along the Siskiyou Trail around Mount Shasta, catering to these early adventuresome tourists and mountaineers.

In the early 20th century, the Pacific Highway followed the track of the Siskiyou Trail to the base of Mount Shasta, leading to still more access to the mountain. Today's version of the Siskiyou Trail, Interstate 5, brings thousands of people a year to Mount Shasta.

February 13–19, 1959 the Mount Shasta Ski Bowl obtained the record of 15.75 feet (480 cm) for the most snowfall during one storm in the U.S.

It was declared a National Natural Landmark in December 1976.

Religion and legends

Main article: Legends of Mount Shasta

Sunrise on Mount Shasta

The lore of some of the Klamath Tribes in the area held that Mount Shasta is inhabited by the Spirit of the Above-World, Skell, who descended from heaven to the mountain's summit at the request of a Klamath chief. Skell fought with Spirit of the Below-World, Llao, who resided at Mount Mazama by throwing hot rocks and lava, probably representing the volcanic eruptions at both mountains.

Italian settlers arrived in the early 1900s to work in the mills as stonemasons and established a strong Catholic presence in the area. Many other faiths have been attracted to Mount Shasta over the years—more than any other Cascade volcano. Mount Shasta City and Dunsmuir, California, small towns near Shasta's western base, are focal points for many of these, which range from a Buddhist monastery (Shasta Abbey, founded by Houn Jiyu-Kennett in 1971) to modern-day Native American rituals. A group of Native Americans from the McCloud River area practice rituals on the mountain.

Mount Shasta has also been a focus for non-native American legends, centered on a hidden city of advanced beings from the lost continent of Lemuria. The legend grew from an offhand mention of Lemuria in the 1880s, to a description of a hidden Lemurian village in 1925. In 1931, Wisar Spenle Cerve wrote Lemuria: the lost continent of the Pacific, published by the Rosicrucians, about the hidden Lemurians of Mount Shasta that cemented the legend in many readers' minds.

In August 1987, believers in the spiritual significance of the Harmonic Convergence described Mount Shasta as one of a small number of global "power centers". Mount Shasta remains a focus of "New Age" attention.

Geology

Satellite (Landsat 8) view of Mount Shasta

About 593,000 years ago, andesitic lavas erupted in what is now Mount Shasta's western flank near McBride Spring. Over time, an ancestral Mount Shasta stratovolcano was built to a large but unknown height; sometime between 300,000 and 360,000 years ago the entire north side of the volcano collapsed, creating an enormous landslide or debris avalanche, 6.5 cu mi (27 km³) in volume. The slide flowed northwestward into Shasta Valley, where the Shasta River now cuts through the 28-mile-long (45 km) flow.

What remains of the oldest of Mount Shasta's four cones is exposed at Sargents Ridge on the south side of the mountain. Lavas from the Sargents Ridge vent cover the Everitt Hill shield at Mount Shasta's southern foot. The last lavas to erupt from the vent were hornblende-pyroxene andesites with a hornblende dacite dome at its summit. Glacial erosion has since modified its shape.

The next cone to form is exposed south of Mount Shasta's current summit and is called Misery Hill. It was formed 15,000 to 20,000 years ago from pyroxene andesite flows and has since been intruded by a hornblende dacite dome.

Nearby Black Butte from Weed, California

There are many buried glacial scars on the mountain which were originally created in recent glacial periods ("ice ages") of the present Wisconsinian glaciation. Most have since been filled in with andesite lava, pyroclastic flows, and talus from lava domes. Shastina, by comparison, has a fully intact summit crater indicating that Shastina developed after the last ice age. Shastina has been built by mostly pyroxene andesite lava flows. Some 9,500 years ago, these flows reached about 6.8 mi (10.9 km) south and 3 mi (4.8 km) north of the area now occupied by nearby Black Butte. The last eruptions formed Shastina's present summit about a hundred years later. But before that, Shastina, along with the then forming Black Butte dacite plug dome complex to the west, created numerous pyroclastic flows that covered 43 sq mi (110 km²), including large parts of what is now Mount Shasta, California and Weed, California. Diller Canyon (400 ft (120 m) deep and 0.25 mi (400 m) wide) is an avalanche chute that was probably carved into Shastina's western face by these flows.

The last to form, and the highest cone, the Hotlum Cone, formed about 8,000 years ago. It is named after the Hotlum glacier on its northern face; its longest lava flow, the 500 ft-thick (150 m) Military Pass flow, extends 5.5 mi (8.9 km) down its northeast face. Since the creation of the Hotlum Cone, a dacite dome intruded the cone and now forms the summit. The rock at the 600 ft-wide (180 m) summit crater has been extensively hydrothermally altered by sulfurous hot springs and fumaroles there (only a few examples still remain).

In the last 8,000 years, the Hotlum Cone has erupted at least eight or nine times. About 200 years ago the last significant Mount Shasta eruption came from this cone and created a pyroclastic flow, a hot lahar (mudflow), and three cold lahars, which streamed 7.5 mi (12.1 km) down Mount Shasta's east flank via Ash Creek. A separate hot lahar went 12 mi (19 km) down Mud Creek. This eruption was observed by the explorer La Pérouse, from his ship off the California coast, in 1786.

Volcanic hazards

During the last 10,000 years Mount Shasta has erupted an average of every 800 years but in the past 4,500 years the volcano has erupted an average of every 600 years. The last significant eruption on Mount Shasta may have occurred about two centuries ago.

Diller Canyon on Shastina from Weed, California

Mount Shasta can release volcanic ash, pyroclastic flows or dacite and andesite lava. Its deposits can be detected under nearby small towns totaling 20,000 in population. Mount Shasta has an explosive, eruptive history. There are fumaroles on the mountain, which show that Mount Shasta is still alive.

The worst-case scenario for an eruption is a large pyroclastic flow, such as what occurred in the 1980 eruption of Mount St. Helens. Since there is ice, such as Whitney Glacier and Mud Creek Glacier, lahars would also result. Ash would probably blow inland, perhaps as far as eastern Nevada. There is a small chance that an eruption could also be bigger resulting in a collapse of the mountain, as happened when Mount Mazama in Oregon collapsed to form what is now called Crater Lake, but this is of much lower probability.

The United States Geological Survey considers Mount Shasta a dormant volcano that will likely erupt in the future and rates it as a very high threat volcano.

Climbing

Mount Shasta's west face. June 2009

Many climbers attempt the summit of Mount Shasta. The summer climbing season runs from late April until October, although many attempts are made in the winter. In winter, Sargents Ridge and Casaval Ridge, to the east and west of Avalanche Gulch respectively, become the most traveled routes, to avoid avalanche danger. Mount Shasta is also a popular destination for backcountry skiing. Many of the climbing routes can be descended by experienced skiers, and there are numerous lower-angled areas around the base of the mountain.

The most popular route on Mount Shasta is Avalanche Gulch route, which begins at the Bunny Flat Trailhead and gains about 7,300 feet (2,200 m) of elevation in approximately 11.5 miles (18.5 km) round trip. The crux of this route is considered to be to climb from Lake Helen, at approximately 10,443 feet (3,183 m), to the top of Red Banks. The Red Banks are the most technical portion of the climb, as they are usually full of snow/ice, are very steep, and top out around 13,200 feet (4,000 m). The Casaval Ridge route is a steeper, more technical route on the mountain's southwest ridge that is best climbed when there's a lot of snow pack. This route tops out to the left (north) of the Red Banks, directly west of Misery Hill. So the final sections involve a trudge up Misery Hill to the summit plateau, similar to the Avalanche Gulch route.

Mount Shasta's west face, as seen from Hidden Valley high on the mountain. The west face gulley is an alternate climbing route to the summit.

No quota system currently exists for climbing Mount Shasta and reservations are not required. However, climbers must obtain a summit pass and a wilderness permit to climb the mountain. Permits and passes are available at the ranger station in Mount Shasta and the ranger station in McCloud, or climbers can obtain self-issue permits and passes at any of the trailheads 24 hours a day.

See also

• List of mountain peaks of North America
  • List of mountain peaks of the United States
    • List of mountain peaks of California
      • List of highest points in California by county
    • List of Ultras of the United States
    • List of volcanoes in the United States
• Volcanic Legacy Scenic Byway