This dataset represents the results (9/30/2008) of the Northeastern Aquatic Habitat ClassificationSystem (NAHCS) GIS map for streams and rivers. This classification focused on mapping a stream habitat types across 13 northeastern states (ME, NH, VT, MA, CT, RI, NY, NJ, PA, MD, DC, DE, VA,WV). Stream and river centerlines were extracted from the USGS National Hydrography Dataset Plus (NH-Plus) 2006 1:100,000 data. These reaches were attributed and placed into classes representing their biopysical setting in terms of stream size, gradient, and geology, and expected natural water temperature regime. Please see the attribute descriptions for more information on the variable thresholds and the summary taxonomy. NH Fish and Game Department transfered the TNC attributes to the 1:24,000-scale high-resolution NHD data for New Hampshire.