The Cascade Range

Mountains & Valleys

Mount St. Helens and Mount Ranier in Washington state are two of 13 large volcanoes in the Cascade Range stretching 700 miles from British Columbia to Northern California. Photo courtesy United States Geological Survey (USGS).

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The Cascade Range

Mount Hood in the Cascade Range in Oregon viewed from the South. Photo courtesy Richard Stovall, USGS.

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Although 220 miles away, Mount Rainier towers over Tacoma, WA. Photo courtesy Lyn Topinka.

The impressive Cascade Range runs along the western edge of North America from California into British Columbia. It is famous for its chain of tall volcanoes called the High Cascades that run northsouth along the west coast of North America from British Columbia to the Shasta Cascade area of northern California. The Canadian Cascades, is the Canadian segment of the North American Cascade Volcanic Arc. Located entirely within the Canadian province of British Columbia, it extends from the Cascade Mountains in the south to the Coast Mountains in the north.

The Cascades volcanoes define the Pacific Northwest section of the “Ring of Fire”, a fiery array of volcanoes that rim the Pacific Ocean. As if volcanic hazards were not enough, the “Ring of Fire” is also infamous for its frequent earthquakes.

Where the Sierra Nevada ends, a chain of explosive volcanic centers, the Cascade volcanoes, begins. Within this region, 13 major volcanic centers lie in sequence like a string of explosive pearls.

Although the largest volcanoes like Mount St. Helens get the most attention, the Cascades is really made up of a band of thousands of very small, short-lived volcanoes that have built a platform of lava and volcanic debris. Rising above this volcanic platform are a few strikingly

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Mount Hood dominates the skyline of Portland, OR on a clear day. Photo courtesy Ed Ruttledge, USGS.

large volcanoes that dominate the landscape.

Mount St. Helens and at least six other volcanoes in the Cascade Range have erupted at least once during historical time. Most of the Cascade volcanic areas contain fumaroles, hot springs, or other evidence of subsurface volcanic heat, but only Mount St. Helens and Lassen Peak have erupted within the past century.

Major volcanic centers are Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, Mount Adams, Mount Hood, Mount Jefferson, Three Sisters, Newberry Caldera, Crater Lake (Mount Mazama), Medicine Lake, Mount Shasta, and Lassen Peak.

recent ice age, this volcano has produced some of the largest and most explosive eruptions in the continental United States.

• Snow and ice-covered Mount Baker, located in northern Washington, is the highest peak in the North Cascades 10,781 ft and the northernmost volcano in the continental United States.

Most Active Cascade Volcanoes

The following volcanoes are among the most active in the Cascade Range.

• Crater Lake partly fills one of the most visually spectacular calderas of the world, an 5-by-6-mile basin more than a half mile deep formed by the collapse of the volcano known as Mount Mazama during a series of explosive eruptions about 7,700 years ago. With a depth of 1,949 ft, Crater Lake is the deepest lake in the United States.

• Glacier Peak is the most remote of the five active volcanoes in Washington State, and more than a dozen glaciers descend its flanks, prompting its name. Glacier Peak is not prominently visible from any major population center, and so its attractions, as well as its hazards, tend to be overlooked. Yet since the end of the most

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Crater Lake in Oregon is the deepest lake in the United States. Photo courtesy David Ramsey, USGS.

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Mount Shasta looming over the town of Weed, CA. Photo courtesy Mark Stensaas.

• Mount Hood, Oregon’s highest peak, forms a prominent backdrop to the state’s largest city, Portland, and contributes valuable water, scenic, and recreational resources that help sustain the agricultural and tourist segments of the economies of surrounding cities and counties. The volcano has erupted episodically for about 500,000 years and hosted two major eruptive periods during the past 1,500 years.

• Mount Rainier, the highest peak in the Cascade Range at 14,410 ft, forms a dramatic backdrop to Seattle and the Puget Sound region. During an eruption 5,600 years ago the once-higher edifice collapsed to form a large crater open to the northeast much like that at Mount St. Helens after 1980.

• Prior to 1980, Mount St. Helens had the shape of a conical, youthful volcano sometimes referred to as the Mount Fuji of America. During the 1980 eruption the upper 1,300 ft of the summit was removed by a huge debris avalanche, leaving a 2 1.2 x 2.2 mile horseshoeshaped crater now partially filled by a lava dome and a glacier.

• Newberry Volcano in Oregon is the largest volcano in the Cascades volcanic arc and covers an area the size of Rhode Island. Unlike familiar cone-shaped Cascades volcanoes, Newberry was built into the shape of a broad shield by repeated eruptions over the past 400,000 years.

• The Three Sisters in Oregon lie within a broad area of densely spaced volcanic vents that, in the Cascades, is

South, Middle and North Sister volcanoes viewed from the south. Photo courtesy USGS.

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duplicated only in southern Washington and Northern California.

Four U.S. National Parks in

the Cascade Range

• Mount Rainier National Park was established in 1899 as the fourth national park in the United States. The park encompasses 236,381 acres including Mount Rainier, the highest peak in the Cascade range. Approximately 2 million people visit the park annually to explore the complex volcanic ecosystem. The climate and environment at the Park includes lowland forests, wetlands, alpine tundra, and the most glaciated mountain in the contiguous United States with 26 named glaciers.

• Crater Lake National Park established in 1902 as the fifth national park

Seismic Network scientists check data on Mount Baker, Washington.

in the United States. It is the only national park in Oregon. The park encompasses the caldera of Crater Lake, a remnant of a destroyed volcano, Mount Mazama, and the surrounding hills and forests.

• Lassen Volcanic National Park in California was established in 1916 while its namesake peak was erupting. The park includes the most extensive and active thermal areas in the United States outside Yellowstone National Park.

The park and Lassen Peak take their name from Peter Lassen, one of the first white settlers in the northern Sacramento Valley.

All four types of volcanoes found in the entire world are represented in Lassen Volcanic National Park— shield (Prospect Peak), plug dome (Lassen Peak), Cinder Cone (Cinder Cone), and Composite (Brokeoff Volcano) volcanoes.

• North Cascades National Park is located in the state of Washington. The park was established in 1968. It features rugged mountain peaks and protects portions of the North Cascades range.

The Cascade Range Volcanoes provide some of the most spectacular mountain views in the continental United States, and are a must see for any North American traveler.

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