Landslide conditions along the Ferry County highway parallelling Lake Roosevelt from Kettle Falls to the mouth of the Spokane River, Washington

As part of the program of the U.S. Geological Survey, landslides are being studied in several localities in the United States. These studies are directed toward assembling criteria for recognition of landslides, classification, and cataloging of remedial or control methods that have been effective.  In the gorge of the Columbia Ricer in Washington, landslides of large magnitude have been active intermittently since the valley was first incised.  Closure of Grand Coulee Dam, with the consequent rise of water forming Franklin D. Roosevelt Lake, has introduced the factor of a rising and fluctuating water table that accentuates the incidence of landsliding.  This area was selected for study because of the magnitude of the landslides and the unknown but significant influence of a fluctuating water table.  Data resulting from the studies will be summarized in a final report.