The DEM was developed through the TOPOGRID command in ARCGrid (ver 8.3). Datasets used in the Topogrid command were:
1. Digital line graphs of 1:24,000 scale topographic contours (20 and 40 foot contour interval).
2. Digital Line Graphs of 1:24,000 National Hydrography Dataset (NHD) streams, lakes and water bodies.
3. Selected digital point spot height elevations scaled from 1:24,000 scale USGS topographics maps.
The original DEM was then converted to NAVD88 vertical datum from the NGVD29 through use of the VERTCON software distributed by the NGS.