The Johnson Creek landslide is located along the Oregon coast near the city of Newport. The landslide has a long history of impacting U.S. Highway 101, which passes over the middle section of the slide. The slide is up to 26 m thick, 200 m long, and 360 m wide, and occurs within the Astoria Formation of Miocene age. At the landslide location, the Astoria formation consists of siltstone, sandstone, mudstone and tuffaceous claystone, and dips 15-20 degrees to the west. Up to a 20 m wide graben defines the headscarp of the slide, and the toe daylights near the beach below the coastal cliff. Total movement of the slide, as estimated from geologic cross-sections, is 28 m horizontally and 6 m vertically. The most recent significant movement of the slide occurred in early 2002, when it moved approximately 25 cm horizontally and several centimeters vertically. For more information, please see: http://landslides.usgs.gov/monitoring/johnson_creek/ Also, see: Preliminary Results of Subsurface Exploration and Monitoring at the Johnson Creek Landslide, Lincoln County, Oregon: http://pubs.usgs.gov/of/2007/1127/
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