"During the week of February 4, 1996, cumulative rainfall levels of up to 23 in. fell in areas of Oregon, Washington, and Idaho. Combined records of rainfall and water equivalent of snowmelt were as high as 39 in. for this period in the Gifford Pinchot National Forest of southern Washington (National Resources Conservation Service, water and Climate Center, Portland, Oregon). Areas of highest rainfall intensities were centered on the Oregon-Washington border. Estimates of damage from the floods and landslides exceed $300 million (FEMA Interagency Hazard Mitigation Team, 1996) in Washington and Oregon alone. [...] The following text describes in greater detail the areas of high, moderate, and low landslide concentrations, noteworthy individual landslide sites, factors affecting landslide concentrations, and estimations of the landslide hazards that potentially still exist."
Geological Survey (U.S.)
Harp, Edwin L.; Cannon, Susan H.; Wilson, Raymond C. . . .