Which volcanic mountain range in the Pacific Northwest includes Mount St. Helens?

The Cascade Range is the volcanic mountain range of the Pacific Northwest that includes Mount St. Helens.

The Cascades extend roughly 1,100 kilometres from southern British Columbia through Washington and Oregon to Northern California. They form part of the American Cordillera and include both non-volcanic mountains in the North Cascades and the prominent volcanic peaks of the High Cascades.

Their volcanoes are linked to the Cascadia subduction zone, where the Juan de Fuca Plate sinks beneath the North American Plate. Water released from the descending oceanic plate helps trigger melting in the mantle, producing magma that feeds the Cascade volcanoes.

Mount St. Helens is among the range's best-known volcanoes. Its catastrophic 1980 eruption dramatically reshaped the surrounding landscape, while smaller eruptions occurred from 2004 to 2008. Mount Rainier is the highest peak in the range, not Mount St. Helens.