Cascade Range

Lore & Background

The Cascade Range extends from Lassen Peak in northern California northward to the confluence of the Nicola and Thompson rivers in British Columbia. In Canada, the Fraser River separates the Cascades from the Coast Mountains, while the Willamette Valley divides the range from the upper Oregon Coast Range. The range includes both non-volcanic mountains, particularly in the rugged North Cascades, and the prominent volcanoes known as the High Cascades. These volcanoes often rise twice the height of surrounding peaks, with a visual height of one mile or more. The highest peak is Mount Rainier in Washington. The northern portion, north of Rainier, is called the North Cascades in the United States and the Cascade Mountains in Canada, extending to Lytton Mountain. This region is extremely rugged, with steep, glaciated peaks and deep valleys creating great local relief. The southern Canadian Cascades, especially the Skagit Range, resemble the North Cascades geologically, while the northern and northeastern parts are less glaciated and more plateau-like. The range lies near the Pacific Ocean and receives heavy rain and snowfall on its western slopes due to prevailing westerly winds and orographic lift, with annual snow accumulations reaching up to significant depths. The western slopes are densely forested with Douglas-fir, western hemlock, and red alder, while the drier eastern slopes feature ponderosa pine, western larch, mountain hemlock, and subalpine fir. The eastern foothills experience a rain shadow effect, receiving much less rainfall. The Columbia River Gorge is the only major break in the range within the United States, carved as the Cascades rose during the late Miocene. The range is part of the Pacific Ring of Fire, and all eruptions in the contiguous United States over the last 200 years have come from the Cascade Volcanoes, including Lassen Peak from 1914 to 1921 and the major 1980 eruption of Mount St. Helens, with minor eruptions continuing as recently as 2004 to 2008.

Reader's Guide

The Cascade Range is part of the Pacific Ring of Fire, and all eruptions in the contiguous United States over the past two centuries have originated from its volcanoes. The most recent major events were Lassen Peak’s activity from 1914 to 1921 and the catastrophic 1980 eruption of Mount St. Helens, which also had minor eruptions as recently as 2004 to 2008. The range forms a segment of the American Cordillera, the nearly continuous mountain chain running the length of the Americas. Ecologically, the western slopes receive immense rain and snow from prevailing Pacific winds via orographic lift, with annual snow accumulations exceeding 1,000 inches in some areas—Mount Baker set a national single-season record in 1998–99, and Mount Rainier’s Paradise station held the previous record. These wet slopes support dense forests of Douglas-fir, western hemlock, and red alder, while the drier eastern slopes, sheltered by a rain shadow, host ponderosa pine, western larch, mountain hemlock, and subalpine fir. The range is dotted with national parks and protected areas, including North Cascades, Mount Rainier, Crater Lake, and Lassen Volcanic National Parks, and the northern half of the Pacific Crest Trail follows its spine. Historically, Indigenous peoples named many peaks—such as Tahoma for Mount Rainier and Louwala-Clough for Mount St. Helens—before British explorer George Vancouver charted the area in 1792, bestowing English names like Mount Baker, Mount Rainier, Mount Hood, and Mount St. Helens, though he did not name the range itself.

Did You Know?

• The Cascade Range is listed as a mountain range by length at 1,100 km (680 mi) in the source.
• The range is a section of the North American Cordillera, which is listed at 6,400 km (4,000 mi).
• All eruptions in the contiguous United States over the last 200 years have been from the Cascade Volcanoes.