DESCRIPTION:
Mount Hood Debris Flows, September 30 - October 1, 2000

Submitted at 17:00 PST, November 7, 2000

Volcanoes in the Cascade Range are all at normal levels of background seismicity. These include Mount Baker, Glacier Peak, Mount Rainier, Mount Adams, and Mount St. Helens in Washington State; Mount Hood, Mount Jefferson, Three Sisters, Newberry, and Crater Lake, in Oregon; and Medicine Lake, Mount Shasta, and Lassen Peak in northern California.

Mount Hood debris flows of September 30 to October 1, 2000: Intense rainfall on September 30 to October 1, 2000, triggered a series of landslides and debris flows in several drainages on Mount Hood. The largest flows occurred in White River and Newton Creek valleys on the east and south flank. Both streams were diverted from their channels and severely damaged two sections of Oregon Highway 35, an important link between I-84 and US 26, and an important recreational highway that provides access to Mount Hood Meadows Ski Area. The Oregon Department of Transportation reopened the highway on October 27; cost of repairs could exceed $1 million. Views of the damaged highway can be found at http://www.odot.state.or.us/region1/.

USGS Cascades Volcano Observatory, the Pacific Northwest Seismograph Network at the University of Washington, and the USGS Northern California Seismic Network and Volcano Hazards Team in Menlo Park, California, monitor the major volcanoes in the Cascade Range of northern California, Oregon, and Washington.