Comment:

The digital maps presented here were originally published as hard copy maps in the Coastal Zone Atlas of Washington between 1978 and 1980. The data extends only 200 ft inland from the shore Although the Atlas has been out of print for many years, the maps contain information that remain the basis for local planning decisions. After receiving multiple requests for electronic versions of portions of the Atlas, an effort was made to scan, georeference and digitize aspects of the Atlas, beginning with the slope stability maps. These maps indicate the relative stability of coastal slopes as interpreted by geologists based on aerial photographs, geological mapping, topography, and field observations. Such methods are standard, but may occasionally result in some unstable areas being overlooked and in some stable areas being incorrectly identified as unstable. Further inaccuracies are introduced to the data through the process of converting the published maps into digital format. Important land use or building decisions should always be based on detailed geotechnical investigations. This mapping represents conditions observed in the early and mid-1970s. Shorelines and steep slopes are dynamic areas and many landslides have occurred since that time that are not reflected on these maps. Subsequent human activities may have increased or decreased the stability of some areas.