This landslide inventory service contains layers pertaining to landslides and related features in Washington State. The data in the lidar-based landslide inventory is compiled using high quality lidar data and following the methods of Slaughter and others (2017). These methods closely follow, and modify where necessary, the Oregon Department of Geology and Mineral Industries (DOGAMI) protocol described in Special Paper 42 (Burns and Madin, 2009). As additional high quality lidar is obtained, and as mass movements occur, the inventory will continue to be revised and updated; because of these caveats the inventory may not contain all the mass movements within an area that mapping appears to be completed.

The landslide compilation layer contains landslides compiled from a variety of sources, spanning the past few decades. The Landslide Compilation contains landslides from the following sources: (1) Landslides that are mapped within 1:24,000-scale geologic mapping (not statewide) and our statewide 1:100,000-scale geologic map compilation; (2) a miscellaneous compilation of pre-existing landslide data from several sources, including the Washington Geological Survey, the Department of Natural Resources’ Forest Practices Division, and other federal and private entities; (3) landslides mapped as part of Watershed Analysis efforts for the Forest Practices Board; (4) reconnaissance-scale mapping of landslides associated with significant landslide events; and (5) a study of near-shore landforms along the Salish Sea.