The Geopspatial Fabric provides a consistent, documented, and topologically connected set of spatial features that create an abstracted stream/basin network of features useful for hydrologic modeling.The GIS vector features contained in this Geospatial Fabric (GF) data set cover the lower 48 U.S. states, Hawaii, and Puerto Rico. Four GIS feature classes are provided for each Region: 1) the Region outline ("one"), 2) Points of Interest ("POIs"), 3) a routing network ("nsegment"), and 4) Hydrologic Response Units ("nhru"). A graphic showing the boundaries for all Regions is provided at http://dx.doi.org/doi:10.5066/F7542KMD. These Regions are identical to those used to organize the NHDPlus v.1 dataset (US EPA and US Geological Survey, 2005). Although the GF Feature data set has been derived from NHDPlus v.1, it is an entirely new data set that has been designed to generically support regional and national scale applications of hydrologic models. Definition of each type of feature class and its derivation is provided within the <dataqual><lineage> section of this metadata document. The first <procstep> entry in that section provides an overview of the delineation process, with each subsequent <procstep> corresponding to one of the four types of feature. These <procstep> entries describe the derivation of feature types in the order in which they are created. Minimal attribution (feature size, location, and routing connectivity) is provided for the feature classes within the GF Feature data set. More extensive feature attribution is published separately as individual tables of attributes(for example, http://dx.doi.org/doi:10.5066/F7RX9937) or via entire configurations of tables engineered to satisfy particular watershed models (for example, http://dx.doi.org/doi:10.5066/F7WM1BF7).