Volcano Profile: Mount Adams


Location: Yakima County, WA

Elevation: 3,742 m (12,277 ft)


Mount Adams is volumetrically the largest volcano in the Pacific Northwest. It is actually a cluster of volcanic vents that erupted andesitic lava from the vent cluster rather than a single vent. The Mount Adams system is one of the youngest in the Cascade Range and is situated further inland than most Cascade volcanoes.

Distribution of lava flows and lahars mapped at the surface compared to hazard zones (gray shaded areas). Much of the volcanic deposits have been either eroded or buried by rivers, glaciers, and human development.


There have been no historical eruptions in the Mount Adams volcanic field. The volcanic center first erupted between 520,000 and 500,000 years ago, and continued up to about 1,000 years ago. However, there were a series of debris avalanches and lahars between ~600 and 300 years ago.

Hydrothermal alteration is present on the main cone as well as at numerous locations along the slope. Fumarole activity was reported at the summit from miners trying to extract sulfur from the crater in the 1930s, but later reconnaissance trips did not reveal any fumaroles—only the faint smell of sulfur.

Are You Volcano Ready?

  • Get to know your local volcano’s hazards
  • Register for notifications about the volcano’s activity
  • Make a plan to prepare your entire family for an emergency



Visit the USGS website for more information on how to be volcano ready, view interpretive signs, and find lahar evacuation routes.

Click on the image (left) for a link to the poster.

Further Reading



Volcano Hazards in the Mount Adams Region




Thanks for following along with Volcano Preparedness Month. We hope you had a blast!