Top 10 Volcanoes in the Cascades
The Cascade Range is the arc above the Juan de Fuca Plate's slow subduction beneath North America. Most Cascade volcanoes look like quiet snowy peaks for decades, then erupt with little warning. The 1980 St Helens event reminded the world that this is a live arc, not a museum.
1. Mount St Helens (Washington)
The 1980 eruption killed 57 people and ejected the upper 400 m of the mountain in a lateral blast. Today a national volcanic monument with visitor centres at Coldwater Lake and Johnston Ridge. The dome inside the crater is still slowly rebuilding.
2. Mount Rainier (Washington)
The most dangerous volcano in the Cascades because of its proximity to Seattle-Tacoma. A 4,392-m glaciated stratovolcano; the lahar risk on the lower flanks is the focus of intensive monitoring. Climbed in two days under permit.
3. Mount Hood (Oregon)
The 3,429-m peak overlooking Portland, last erupting in the 1860s. The Timberline Lodge ski area runs on its southern flank. Climbed in long day-trips with mountaineering gear.
4. Mount Shasta (California)
A 4,322-m double-peaked stratovolcano in northern California, last eruption around 1786. A spiritual centre for many groups and one of the largest stratovolcanoes by volume in the Cascades.
5. Mount Baker (Washington)
A 3,286-m glaciated volcano in the north Cascades. Active fumaroles at the Sherman Crater have been recorded; the climbing routes are popular in summer.
6. Lassen Peak (California)
A 3,187-m lava-dome volcano that erupted spectacularly in 1914–17 — the most recent magmatic eruption in the contiguous US before St Helens. Lassen Volcanic National Park is built around it.
7. Glacier Peak (Washington)
A remote 3,213-m stratovolcano that is one of the most active in the Cascades. Last major eruption around 1700, but small Holocene events have been frequent.
8. Mount Adams (Washington)
A 3,743-m broad shield-stratovolcano in southern Washington, last erupting in the late Holocene. Climbed as a long but non-technical glacier trip on its south side.
9. Three Sisters (Oregon)
A trio of stratovolcanoes (South, Middle and North Sister) east of Bend. The South Sister is the youngest and shows recent ground deformation suggesting magma movement.
10. Mount Mazama (Crater Lake, Oregon)
The volcano that erupted catastrophically about 7,700 years ago and collapsed into the caldera that now holds the deepest lake in the United States. Wizard Island in the lake is a post-collapse cone.
How the arc works
The Juan de Fuca Plate is being subducted beneath the North American Plate at about 4 cm/year. Slab dehydration generates the arc magma; slow plate motion means infrequent but very large eruptions when they occur. The 1980 St Helens event was a relatively small expression.
Safety and access
All Cascade volcanoes are monitored by the USGS Cascades Volcano Observatory. Most have well-marked hiking trails and accessible viewpoints. Climbing the higher peaks requires mountaineering experience and, often, permits.
On the map
Open the map and filter to the Cascade Range to see the arc draw a 1,100-km line from Mount Garibaldi in British Columbia to Lassen Peak in California — a single subduction story across three states and a province.