Cascade Range

Mount Rainier in Washington State is the highest volcano of the Cascade Range. Although not especially active recently it has a significant cover of ice and snow, which if melted rapidly would produce catastrophic flooding of nearby populated areas.

Volcanic mountains in northwestern USA and southwestern Canada, extending 1,120 km/700 mi from northern California through Oregon and Washington as far as the Fraser River in British Columbia, Canada. The highest peaks are Mount Rainier (4,392 m/14,408 ft), Mount Shasta (4,317 m/14,163 ft), and Mount Adams (3,751 m/12,306 ft). They are the most active volcanoes in the USA, excluding Alaska and Hawaii; Mount St Helens in Washington (2,549 m/8,364 ft), which had been dormant since 1857, erupted violently in 1980 and 1982.

They are a continuation of the Sierra Nevada range in the south and the Coast Ranges in the north. The core of the Cascade Range is formed by old crystalline rocks but above their crestline are many volcanic cones, whose lava flows have covered much of the lower slopes.