This polygon shapefile contains information on costly regional landslide events in the 50 United States and Puerto Rico. The extents of the regional events were drawn from the published literature and represent the approximate boundaries of extensive landsliding triggered by a single meteorological or seismic event. The regional extents should be considered approximate. In several cases the limits shown represent an arbitrary administrative boundary rather than the extent of landsliding related to a storm or earthquake. Costly events are defined as those where there was public or private property damage or loss of human life. Landslides are defined in a broad manner, to include most types of gravitational mass movement such as rockfalls, debris flows, and the failure of engineered soil materials. Landslide causes include earthquakes, reservoir draw-downs, and heavy precipitation. This is an updated version of the April 2001 map layer. This layer is part of the 1997-2014 edition of the National Atlas of the United States. These data are intended for geographic display and analysis at the national level, and for large regional areas. The data should be displayed and analyzed at scales appropriate for 1:2,000,000-scale data. No responsibility is assumed by the National Atlas of the United States in the use of these data. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
