Create high-resolution NHD from revised DLG data.  This process started with published 1:24,000-scale USGS DLG hydrography files and used DOQs to revise the data.  Features were modified to the DOQ only where compelling evidence of change existed. DLG files were converted to ArcInfo coverages and projected to a common projection (Albers NAD83 meters).   Coverages were then panelled into one coverage and arcs within 12 meters of each other along the neatline were snapped together if the feature type were the same.  Next, the 11-digit Hydrologic Unit Code (HUC) boundary was obtained from the state NRCS office.   The HUC boundary was projected to the Albers projection and used to extract features from the paneled coverage that fell partially or entirely within the boundary.  Where necessary, the HUC boundary was slightly modified to completely include or exclude features that incorrectly overlapped the boundary.  Substantial alterations to the HUC boundary were confirmed on the topographic maps. Next, arcs from the extracted coverage were grouped in order to examine the connectivity of the data set for flow determination.  In some cases it was necessary to correct digitizing errors.  Using available evidence or cartographic judgment, lines called connectors were added to join features that were deemed to have flow between each other.  All arcs were directed downstream and the nodes were prepared to help create artificial paths through 2-D waterbodies and complete the flow through the hydrography network.  The artificial path coverage was combined with the single line stream network to create the drainage network.  The drainage network was grouped again, and each group was directed downstream.  Feature codes (fcodes) were assigned to landmark, network, waterbody features through a crosswalk that converts DLG-3 attributes to fcodes, where an  fcode is a five digit integer that encodes a set of feature type characteristics.  Reach codes and associated attributes were conflated from the 100K NHD data to the 24K drainage network  and 2-D waterbodies.  Several checks were performed to validate the reach transfer process.Any reach codes that could not be maintained are tracked in the Reach Cross Reference table.  New reaches that do not exist in the 100K data were defined according to reach delineation rules (See  New waterbody reaches were assigned to 2-D lake/pond and reservoir features that do not exist in the 100K NHD.  New reaches were assigned reach code values that are sequentially ordered to 2-D and then 1-D reaches.  New 24K reach codes are larger than any existing 100K reach code in the associated Catalog Unit. Additional Geographic Names that exist in the Geographic Names Information System (GNIS) were added to reaches in the 24K dataset. Names for the 24K drainage network were interactively transferred from the vector GNIS coverage.   Additional GNIS names for point and waterbody features were also added.