Cascade Range

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Template:Redirect Image:Mount Adams.jpg The Cascade Range is a mountainous region famous for its chain of tall volcanoes called the High Cascades that run north-south along the west coast of North America from British Columbia to the Shasta Cascade area of northern California. The small part of the range in British Columbia is called the Cascade Mountains or Canadian Cascades.

The Cascades are part of the Pacific Ring of Fire, the ring of volcanoes around the Pacific Ocean. All of the known historic eruptions in the contiguous United States have been from Cascade volcanoes. The two most recent were Lassen Peak in 1914 to 1921 and a major eruption of Mount St. Helens in 1980. Minor eruptions of Mount St. Helens have also occurred, most recently in 2005.

Image:Mount Jefferson.jpg

Contents

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History

Native Americans have inhabited the area for thousands of years and developed their own myths and legends concerning the Cascades. According to some of these tales, Mounts Baker, Jefferson, and Shasta were used as refuge from a great flood. Other stories, such as the Bridge of the Gods tale, had various High Cascades such as Hood and Adams, act as god-like chiefs who made war by throwing fire and stone at each other. St. Helens with its pre-1980 graceful appearance, was regaled as a beautiful maiden for whom Hood and Adams feuded. Among the many stories concerning Mount Baker, one tells that the mountain was formerly married to Mount Rainier and lived in that vicinity. Then, because of a marital dispute, she picked herself up and marched north to her present position. Native tribes also developed their own names for the High Cascades and many of the smaller peaks, the most well-known to non-natives being Tahoma, the Lushootseed name for Mount Rainier.

The legendary and diverse ethnographic history of the Cascade Range is too complex to recount here, except to say that the spine of the range forms the divide between the Interior Salish and Coast Salish language groupings, and mythographically between the realm of Coyote on the east and that of the Transformers and the spirit-world of the Coast on the west.

Legends associated with the great volcanoes are many, as well as with other peaks and geographical features of the range, including its many hot springs and waterfalls and rock towers and other formations. Stories of Tahoma - today Mount Rainier and the namesake of Tacoma, Washington - allude to great, hidden grottos with sleeping giants, apparitions and other marvels in the volcanoes of Washington, and Mount Shasta in California is almost too famous for its New Age mystical associations with everything from Atlanteans to aliens to elves and, as everywhere in the Cascades, Sasquatch or Bigfoot.

In the spring of 1792 British navigator George Vancouver entered Puget Sound and started to give English names to the high mountains he saw. Mount Baker was named for Vancouver's third lieutenant, the graceful Mount St. Helens for a famous diplomat, Mount Hood was named in honor of Samuel Hood, 1st Viscount Hood (an admiral of the Royal Navy) and the tallest Cascade, Mount Rainier, is the namesake of Admiral Peter Rainier. Vancouver's expedition did not, however, name the range these peaks belonged to. As marine trade in the Strait of Georgia and Puget Sound proceeded in the 1790s and beyond the summits of Rainier and Baker became familiar to captains and crews (mostly British and American over all others, but not exclusively).

In 1805 the Lewis and Clark expedition passed through the Cascades by using the Columbia River, which for many years was the only practical way to pass that part of the range. Trade on the lower Columbia River, which skirts the southern end of the range, did not occur until after Lewis and Clark in 1806, more specifically as a result of David Thompson's visit on behalf of the Hudson's Bay Company shortly afterwards, and Simon Fraser's journey down the Fraserin 1808. The Lewis and Clark expedition, and the many settlers and traders that followed, met their last obstacle to their journey at the Cascades Rapids in the Columbia River Gorge, a feature on the river now submerged beneath Lake Bonneville. Before long, the great white-capped mountains that loomed above the rapids were called the "mountains by the cascades" and later simply as the "Cascades" (the earliest attested use of this name is in the writings of botanist David Douglas). On their return trip Lewis and Clark's group spotted a high but distant snowy pinnacle that they named for the sponsor of the expedition, U.S. President Thomas Jefferson.

The course of political history in the Pacific Northwest saw the spine of the Cascade Range being proposed as a boundary settlement during the Oregon Dispute of 1846, which was rejected by the United States which insisted on the 49th Parallel, which cuts across the range just north of Mount Baker. Throughout the period of dispute and up to the creation of the Crown Colony of British Columbia in 1858, the edge of the range along the Columbia and Okanogan Rivers formed the main express route of the Hudson's Bay Company's busy traffic, and passes across the range were used by HBC staff at Forts Nisqually and Puyallup. The vast majority of non-native residents of the Cascade Range region until about 1840 were British subjects, most of mixed French-native blood and some Hawaiians and blacks as well as Scots who were the backbone of Hudson's Bay Company administration.

American settlement of the flanks of the Coast Range did not occur until the early 1840s, at first only marginally. Following the Oregon Treaty the inward flux of migration from the Oregon Trail intensified and the passes and back-valleys of what is now the state of Washington became explored and populated, and it was not long after that railways followed. Despite its being traversed by several major freeways and rail lines, and its lower flanks subjected to major logging in recent decades, large parts of the range remain intense and forbidding alpine wilderness. Most of the northern half of the High Cascades, from Rainier north, have been preserved by US national or BC provincial parks or other forms of protected area.

The Canadian side of the range has a history that includes the Fraser Canyon Gold Rush of 1858-60 and its famous Cariboo Road, as well as the older Hudson's Bay Company Brigade Trail from the Canyon to the Interior, the Dewdney Trail and older routes which connected east to the Similkameen and Okanagan valleys.

The southern mainline of the CPR penetrated the range via the passes of the Coquihalla River, along one of the steepest and snowiest routes in the entire Pacific Cordillera. The railway's roadbed, now decommissioned, is a popular tourist recreation destination, the Othello Tunnels, a hiking and biking trail near Hope, B.C. (Waystations along the line were given Shakespearean names by the local CBC administrator). The pass itself is used by BC Highway 5 (Coquihalla Highway), a government megaproject built as part of the Expo 86 spending boom of the 1980s, which is now the main route from the Coast to the British Columbia Interior. Traffic formerly went via the Fraser Canyon, to the west, or via Allison Pass and Manning Park along Highway 3 to the south, near the border.

Image:Lassen-Peak-Large.jpg

The Barlow Trail was the first established land path for U.S. settlers through the Cascade Range in 1845, and formed the final overland link for the Oregon Trail (previously, settlers had to raft down the treacherous rapids of the Columbia River). The Barlow Trail left the Columbia at Hood River and passed along the south side of Mt. Hood at Government Camp, terminating in Oregon City. There is an interpretive site there now at "The End of The Oregon Trail." The trail was constructed as a toll road - $5/wagon - and was very successful.

With the exception of the 1915 eruption of remote Lassen Peak in Northern California, the range was quiet for more than a century. Then, on May 18, 1980, the dramatic eruption of little-known Mount St. Helens shattered the quiet and brought the world's attention to the range. Geologists were also concerned that the St. Helens eruption was a sign that long-dormant Cascade volcanoes might become active once more, as in the period from 1800 to 1857 when a total of eight erupted. None have erupted since St. Helens, but precautions are being taken nevertheless, such as the Mount Rainier Volcano Lahar Warning System in Pierce County, Washington.[1]

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Geography

Image:Mount-rainier-over-tacoma.jpg

At its southern end the range is about 30 to 50 miles (50 to 80 km) wide and 4500 to 5000 feet (1370 to 1520 m) high but is higher and 80 miles (130 km) wide in northern Washington. The tallest volcanoes of the Cascades (called the High Cascades) dominate the rest of the range, often standing twice the height of the surrounding mountains and thus often have a visual height of a mile (1.6 km) or more. The tallest peaks, such as the 14,411 foot (4392 m) high Mount Rainier, dominate their surroundings for 50 to 100 miles (80 to 160 km).

The northern part of the range, north of Mount Rainier is extremely rugged, with many of the lesser peaks steep and glaciated. The valleys are quite low however, and major passes are only about 1000 m (3300 ft) high.

Because of the range's proximity to the Pacific Ocean, precipitation is substantial, especially on the western slopes, with annual accumulations of up to 150 inches (3800 mm) in some areas—Mount Baker, for instance, apparently recorded the largest single-season snowfall on record in the world in 1999—and heavy snowfall as low as 2000 feet (600 m). Most of the High Cascades are therefore white with snow and ice year-round. The western slopes are densely covered with Douglas-fir, Western Hemlock and Red alder, while the drier eastern slopes are mostly Ponderosa Pine, with Western Larch at higher elevations. Annual rainfall drops to 8 inches (200 mm) on the eastern foothills due to a rainshadow effect.

Beyond the foothills is an arid plateau that was created 16 million years ago as a coalescing series of layered flood basalt flows. Together these sequences of fluid volcanic rock form a 200,000 square mile (520,000 km2) region out of western Washington, Oregon, and parts of Northern California and Idaho called the Columbia River Plateau.

The Columbia River Gorge is the only major break in the American part of the Cascades. When the Cascades started to rise 7 million years ago in the Pliocene, the Columbia River drained the relatively low Columbia River Plateau. As the range grew, the Columbia was able to keep pace, creating the gorge and major pass seen today. The gorge also exposes uplifted and warped layers of basalt from the plateau.

Another major pass was cut by the Fraser River through mainly non-volcanic rocks in the British Columbian part of the range. This group of mountains are often called the "Coast Mountains" but are in fact structurally part of the Cascades. Mount Garibaldi and its associated group of volcanoes are in this part of the range. The country rocks here were derived from a mini-continent that grafted itself to this part of North America 50 million years ago, carrying along its own subduction zone (see Juan de Fuca Plate).

See also: Map of the Southern Oregon Cascade Range

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Human uses

Soil conditions for farming are generally excellent, especially downwind of volcanoes. This is largely due to the fact that volcanic rocks are often rich in minerals such as potassium and decay easily. Volcanic debris, especially lahars, also have a leveling effect and the storage of water in the form of snow and ice is also important. Much of that water eventually flows into reservoirs where it is used for recreation before its potential energy is captured to generate hydroelectric power before being used to irrigate crops.

In addition, there is a largely untapped amount of geothermal power that can be generated from the Cascades. The USGS Geothermal Research Program has been investigating this potential. Some of this energy is already being used in places like Klamath Falls, Oregon where volcanic steam is used to heat public buildings. The highest recorded temperature found in the range is 510° F (265° C) at 3075 feet (937 m) below Newberry Caldera's floor.

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High Cascades

Image:Cascade Range map.png Listed north to south:

  • Mount Garibaldi (British Columbia) - heavily eroded by glaciers and has three principal peaks. Mount Garibaldi is not part of the Cascade Range, but of the Pacific Ranges of the Coast Mountains complex. It is nonetheless classified in the Cascade group or family of volcanoes. But while other volcanoes to the north in the Pacific Ranges are not considered part of the Cascades, they, however, are part of the Garibaldi Volcanic Belt.
  • Mount Baker (Near the United States-Canada border) - highest peak in northern Washington. It still shows some steam activity from its crater, though it is considered dormant.
  • Glacier Peak (northern Washington) - secluded and relatively inaccessible peak. Contrary to its name, its glacial cover isn't that extensive. The volcano is surprisingly small in volume, and gets most of its height by having grown atop a nonvolcanic ridge.
  • Mount Rainier (southeast of Tacoma, Washington) - highest peak in the Cascades, it dominates the surrounding landscape. There is no other higher peak northwards until the Yukon-Alaska-BC border apex beyond the Alsek River.
  • Mount St. Helens (southern Washington) - Erupted in 1980, completely leveling the surrounding area and sending ash across the northwest. The northern part of the mountain was destroyed in the blast (see 1980 Mount St. Helens eruption).
  • Mount Adams (east of Mount St. Helens) - the second highest peak in Washington.
  • Mount Hood (northern Oregon) - the highest peak in Oregon and the most frequently climbed major peak in the Cascades.
  • Mount Jefferson (northcentral Oregon) - the second highest peak in Oregon.
  • Three Fingered Jack (northcentral Oregon) - Highly eroded Pleistocene volcano.
  • Mount Washington (between Santiam and McKenzie passes) - a highly eroded shield volcano. [2]
  • Three Sisters (near the city of Bend, Oregon) - South Sister is the highest and youngest, with a well defined crater. Middle Sister is more pyramidal and eroded. North Sister is the oldest and has a crumbling rock pinnacle.
  • Broken Top (to the southeast of South Sister) - a highly eroded extinct stratovolcano. Contains Bend Glacier.
  • Newberry Volcano and Newberry Caldera - isolated caldera with two crater lakes. Very variable lavas. Flows from here have reached the city of Bend.
  • Mount Bachelor (near Three Sisters) - a geologically young (less than 15,000 years) shield-to-stratovolcano which is now the site of a popular ski resort.
  • Mount Bailey (north of Mount Mazama)
  • Mount Thielsen (east of Mount Bailey) - highly eroded volcano with a prominent spire, making it the Lightning Rod of the Cascades.
  • Mount Mazama (southern Oregon) - better known as Crater Lake, which is a caldera formed by a catastrophic eruption which took out most of the summit roughly 6,900 years ago. Mt. Mazama is estimated to have been about 11,000 ft. elevation prior to the blast.
  • Mount McLoughlin (near Klamath Falls, Oregon) - presents a symmetrical appearance when viewed from Klamath Lake.
  • Medicine Lake Volcano - a large shield volcano in northern California
  • Mount Shasta (northern California) - second highest peak in the Cascades. Can be seen as far as the Sacramento Valley, 60 miles away, as it is a dominating feature of the region.
  • Lassen Peak (south of Mt. Shasta) - southernmost volcano in the Cascades and the most easily climbed peak in the Cascades, it erupted 1914-1921
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Protected areas

There are four U.S. National Parks in the Cascade Range and many U.S. National Monuments, U.S. Wilderness Areas, and U.S. National Forests. Each classification protects the various glaciers, volcanoes, geothermal fields, rivers, lakes, forests, and wildlife to varying degrees.

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National parks

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National monuments

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Provincial Parks

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References

fr:Chaîne des Cascades ja:カスケード山脈 nl:Kustgebergte no:Kaskadefjellene

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