King County's Elevation (digital ground model - DGM) Database has at its core a high-resolution base from lidar collected in 2002 and 2003. As new elevation data becomes available to infill missing areas (i.e., other sources for bathymetry data as lidar does not collect water areas), or becomes available that improves on the existing lidar base, it is appended to the elevation database.
Where necessary, users may wish to obtain the source and vintage of information in the current database by using this map (or its underlying datafile - p_dgm_source.shp).
The source data file also serves as an index to the various raw data files (zipped ascii files) that may exist for a given area in a location where multiple sources overlap.