The NHD is a comprehensive set of digital spatial data that contain information about surface water features such as lakes, ponds, streams, rivers, springs and wells. The NHD is the surface water feature data component of the USGS’s National Map project. Within the NHD, surface water features are combined to form "reaches," which provide the framework for linking water-related data to the NHD surface water drainage network. These linkages enable the analysis and display of these water-related data in upstream and downstream order. To access The National Map by USGS go to The National Map Viewer and Download Platform.
As the State NHD Steward, the Montana State Library updates and maintains the NHD in partnership with the USGS. MSL offers the high resolution (1:24K) NHD in geodatabase and shapefile formats (refreshed twice a year) projected to the Montana State Plane Coordinate System. Go to the Montana NHD Data Download Page . Additionally, web map services are available for the NHD and watershed boundary dataset here: GIS Portal Web Services.
For more information on the structure of the NHD Geodatabase, see the NHD User Guide . You may also find it helpful to print out the database schema version 2.1 (pdf file). Additional documentation and tutorials can be found at USGS NHD Home under the User Help, NHD Tools, and NHD Applications tabs. Click here for more information about the hierarchical, numeric Hydrologic Unit Codes (HUCs) used by the USGS to identify basins and watersheds.