This forum addressed NSGIC activities that support national efforts to update the National Hydrography Dataset with elevation-derived hydrography as a first step toward building a 3D National Hydrography Dataset. Specific options for NSGIC community participation were discussed. This forum is the first in a series of 3DNHD-related forums intended to explore state and regional 3DHP activities and to derive critical factors affecting the development of 3DHP and the integration of those data into the National Hydrography Dataset.