USGS Volcano Notice - DOI-USGS-CVO-2023-05-19T11:58:15-07:00

Activity Update: All volcanoes in the Cascade Range of Oregon and Washington 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: On the evening of Sunday, May 14, a debris flow in the upper South Coldwater Creek drainage destroyed a bridge over Washington State Route 504, about a mile northeast of Johnston Ridge Observatory (JRO) in the Mount St. Helens National Volcanic Monument (MSHNVM). The debris flow cut off road access and power to JRO, resulting in the loss of signal transmission from several monitoring stations at Mount St. Helens. The number of instruments that remain operational is sufficient to detect increased activity and provide rough earthquake locations. Permanent repairs to the road and power supply could take months or more. In the meantime, the USGS is working with MSHNVM staff on workarounds to restore signal transmission as soon as possible. Seismicity at Mount St. Helens and all other Cascade volcanoes has been at background levels this week.