Newest Volcano Notice

Activity Update: All volcanoes in the Cascade Range of Washington and Oregon are at normal background activity levels. These include Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams in Washington State and Mount Hood, Mount Jefferson, Three Sisters, Newberry, and Crater Lake in Oregon.

Past Week Observations: Over the past week, small earthquakes were detected at Mount Hood, Mount Rainier, Mount Adams, and Mount St. Helens. At Mount Adams, the Pacific Northwest Seismic Network located 10 events ranging from M0.8 to M2.6 on September 27-28, all too small to be felt at the surface.  Seismicity over the past year continues a trend of slightly elevated earthquake activity at Mount Adams that began in fall 2024. Although this represents an increase in rate of seismicity for Mount Adams, the rate remains substantially lower than earthquake rates at its three closest volcanic neighbors: Mount St. Helens, Mount Hood, and Mount Rainier; and all monitoring data remain consistent with background activity levels throughout the Cascade Range. Field work included routine maintenance of monitoring stations at Mount Hood, and a rapid-response field-site repair to restore network connectivity to several Rainier Lahar Detection System stations.