Cascade Range

"Cascades" redirects here. For other uses, see Cascades (disambiguation).

Cascade Range
Cascade Mountains (in Canada) "The Cascades"
Cascades in Washington, with Mount Rainier in the background
Highest point
Peak	Mount Rainier
Elevation	14,411 ft (4,392 m)
Dimensions
Length	700 mi (1,100 km) north-south
Width	80 mi (130 km)
Geography
Countries	United States and Canada
Provinces/States	Oregon, Washington, California and British Columbia
Geology
Rock age	Pliocene

The Cascade Range (or Cascades) is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, and the notable volcanoes known as the High Cascades. The small part of the range in British Columbia is referred to as the Canadian Cascades or, locally, as the Cascade Mountains. The latter term is also sometimes used by Washington residents to refer to the Washington section of the Cascades in addition to North Cascades, the more usual American term, as in North Cascades National Park.

Template:J part of the Pacific Ring of Fire, the ring of volcanoes and associated mountains 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 since, most recently in 2006.

Geography

Map of the Cascade Range showing major volcanic peaks.

The Cascades extend from Lassen Peak (also known as Mount Lassen) in northern California to the confluence of the Nicola and Thompson Rivers in British Columbia. The Fraser River separates the Cascades from the Coast Mountains. The highest volcanoes of the Cascades are called the High Cascades and dominate their surroundings, often standing twice the height of the nearby mountains. They often have a visual height (height above nearby crestlines) of 1 mi (1.6 km) or more. The highest peaks, such as the 14,411 ft (4,392 m) high Mount Rainier, dominate their surroundings for 50 to 100 mi (80 to 161 km).

The northern part of the range, north of Mount Rainier, is known as the North Cascades in the United States but is formally named the Cascade Mountains north of the Canada – United States border, reaching to the northern extremity of the Cascades at Lytton Mountain. Overall, the North Cascades and southwestern Canadian Cascades are extremely rugged, with many of the lesser peaks steep and glaciated, with valleys quite low relative to its peaks and ridges, resulting in great local relief. The southern part of the Canadian Cascades, particularly the Skagit Range, is geologically and topographically similar to the North Cascades, while the northern and northeastern parts are less glaciated and more plateau-like in character, resembling nearby areas of the Thompson Plateau.

Because of the range's proximity to the Pacific Ocean and the region's prevailing westerly winds, precipitation is substantial, especially on the western slopes, with annual accumulations of up to 150 in (3,800 mm) in some areas. For example, Mount Baker recorded the largest single-season snowfall on record in the world in 1999&, with heavy snowfall as low as 2,000 ft (610 m). It is not uncommon for some places in the Cascades to have over 200 in (5,100 mm) of snow accumulation, such as at Lake Helen (near Lassen Peak), one of the snowiest places in the world. 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 9 in (230 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 sq mi (520,000 km²) region out of eastern 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, erosion from the Columbia River 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.

History

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, and 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), while the highest Cascade, Mount Rainier, is the namesake of Admiral Peter Rainier. Vancouver's expedition did not, however, name the mountain range which contained these peaks. 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 did not occur until after Lewis and Clark in 1806, more specifically as a result of David Thompson's visit on behalf of the North West Company shortly afterwards, and Simon Fraser's journey down the Fraser in 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 the Bonneville Reservoir. 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 the name "Cascade Range" 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.

Mount Rainier, with Tacoma, Washington in foreground

Central Washington Cascades

In 1814 Alexander Ross, a fur trader with the North West Company, seeking a viable route across the mountains, explored and crossed the northern Cascades between Fort Okanogan and Puget Sound. His report of the journey is vague about the route taken. He followed the lower Methow River into the mountains. He might have used Cascade Pass to reach the Skagit River. Ross was the first European-American to explore the Methow River area and likely the first to explore the Stehekin River and Bridge Creek region. Due to the difficulty of crossing the northern Cascades and the paucity of beaver, fur-trading companies made only a few explorations into the mountains north of the Columbia River after Ross.

Exploration and settlement of the Cascades region by Europeans and Americans was accelerated by the establishment of a major trading post of the Hudson's Bay Company at Fort Vancouver near today's Portland, Oregon. From this base, Hudson's Bay Company trapping parties traveled throughout the Cascades in search of beaver and other fur-bearing animals. For example, using what became known as the Siskiyou Trail, Hudson's Bay Company trappers were the first non-natives to explore the southern Cascades in the 1820s and 1830s, establishing trails which passed near Crater Lake, Mount McLoughlin, Medicine Lake Volcano, Mount Shasta, and Lassen Peak.

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. The United States rejected the proposal and insisted on the 49th parallel north, 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 Hudson's Bay Company's York Factory Express route, as well the route of fur brigades, followed the Okanogan River along the east edge of the Cascades and the Columbia River through the range. Passes across the range were not well known and little used. Naches Pass was used for driving cattle and horses to Fort Nisqually. Yakima Pass was also used by the Hudson's Bay Company. 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.

Mount Shasta from Siskiyou Trail.

Lassen Peak in California.

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 were 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 British Columbia provincial parks (such as E.C. Manning Provincial Park), 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 Canadian Pacific Railway penetrated the range via the passes of the Coquihalla River, along one of the steepest and snowiest routes in the entire Pacific Cordillera. Near Hope, B.C., the railway roadbed and the Othello Tunnels, now decommissioned, are popular tourist recreation destinations for hiking and bicycling. The pass is used by the 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.

The Barlow Road 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 Road left the Columbia at Hood River and passed along the south side of Mount Hood at Government Camp, terminating in Oregon City. There is an interpretive site there now at "The End of The Oregon Trail." The road was constructed as a toll road — $5/wagon — and was very successful.

In addition, the Applegate Trail was created to allow settlers to avoid rafting down the Columbia River. The Applegate Trail used the path of the California Trail to north-central Nevada. From there, the Applegate Trail headed northwest into northern California, and continued northwest towards today's Ashland, Oregon. From there, settlers would head north along the established Siskiyou Trail into the Willamette Valley.

Cascade eruptions in the last 4000 years

Geology of the Cascade Range-related plate tectonics.

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.

Geology

The Cascades include active volcanic activity, such as with the May 1980 eruption of Mount St. Helens. The tectonics of the region has been extensively studied to help describe the extent of the shifting and volcanic problems.

Human uses and legends

Soil conditions for farming are generally good, especially downwind of volcanoes. This is largely due to the fact that volcanic rocks are often rich in potassium bearing minerals such as Orthoclase 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. These snow capped mountains such as Mt. Hood and Mt.Bachelor are used as ski resorts in the late winter. 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.

Because of the abundance of powerful streams, many of the major westward rivers off the Cascades have been dammed to provide hydroelectric power. One of these, Ross Dam on the Skagit River, created a reservoir which spans the border southeast of Hope, British Columbia, extending into Canada 2 mi (3.2 km). At the foot of the southeast flank of Mount Baker, at Concrete, Washington, the Baker River is dammed to form Lake Shannon and Baker Lake.

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 (266 °C) at 3,075 ft (937 m) below Newberry Volcano's caldera floor.

Indigenous peoples have inhabited the area for thousands of years and developed their own myths and legends concerning the Cascades. In these legends, St. Helens with its pre-1980 graceful appearance, was regarded as a beautiful maiden for whom Hood and Adams feuded. Native tribes also developed their own names for the High Cascades and many of the smaller peaks, including "Tahoma", the Lushootseed name for Mount Rainier; and "Louwala-Clough", meaning "smoking mountain" for Mount St. Helens.

Ecology

Oval-leaf Blueberry on Mount Pilchuck

Main articles: Cascades (ecoregion) and Ecology of the North Cascades

There is a wide range of flora and fauna inhabiting the Cascade Range. The southern part of the Cascades are within what Conservation International defines as the California Floristic Province, an area of high biodiversity.

Black bears, coyotes, bobcats, cougars, Beavers, deer, and elk live in the Cascades, and in the northern mountains, Grizzly bears.

Most of the Cascades' lower and middle elevations are covered in coniferous forest and temperate rainforest; the higher altitudes have areas of alpine tundra and glaciers. Common trees include Western hemlock and Douglas fir.

See also

• Cascade volcanoes
• Cascadia subduction zone
• Geology of the Pacific Northwest
• North Cascades
• List of mountain ranges in Washington
• Cascadia (independence movement)
• List of Cascade range topics

References

• Harris, Stephen L. (2005). Fire Mountains of the West: The Cascade and Mono Lake Volcanoes (3rd ed.). Mountain Press Publishing Company. ISBN 0-87842-511-X.
• Wood, Charles A. (1990). Volcanoes of North America. Cambridge University Press. ISBN 0-521-43811-X. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Fred Beckey. 1973. Cascade Alpine Guide (3 vols.) (The Mountaineers, Seattle).
• Dzurisin, Dan (1997, revised 2000). Living With Volcanic Risk in the Cascades. United States Geological Survey. {{cite book}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Holland, Stuart S. (1976). Landforms of British Columbia: A Physiographic Outline (Bulletin 48). British Columbia Department of Mines and Petroleum Resources. Archived from the original on 2005-05-04.

External links

• Central and Southern Cascades Forests images at bioimages.vanderbilt.edu
• Eastern Cascades Forests images at bioimages.vanderbilt.edu
• Cascade Mountains Leeward Forests images at bioimages.vanderbilt.edu
• British Columbia Mainland Coastal Forests images at bioimages.vanderbilt.edu
• University of Washington Libraries Digital Collections – Dwight Watson Photographs Photographs taken by mountaineer and amateur photographer Dwight Watson of hiking and skiing expeditions in the Cascade and Olympic Mountain ranges of Washington State, ca. 1920s-1960s. Includes, among others, scenic images of Mounts Rainier, Baker, Adams, and Glacier Peak.