NHD_MajorAreas are a subset of the largest double banked stream/river polygon features selected from the High Resolution NHD dataset for Washington State. This subset includes only NHDAreas that have an associated NHD_MajorStream. NHD_MajorStreams are classified as those that have GNIS Names that include "River", or have a Stream Order > 7, or have a GNIS Name that includes "Creek" and is longer than 24 km. NHD_MajorAreas have an NHD_MajorStream flowing through it.The National Hydrography Dataset (NHD) is a feature-based database that interconnects and uniquely identifies the stream segments or reaches that make up the nation's surface water drainage system. This high-resolution NHD, generally developed at 1: 12,000/1:24,000 scale, adds detail to the original 1:100,000-scale NHD. Local resolution NHD is being developed where partners and data exist. The NHD contains reach codes for networked features, flow direction, names, and centerline representations for areal water bodies. Reaches are also defined on waterbodies and the approximate shorelines of the Great Lakes, the Atlantic and Pacific Oceans and the Gulf of Mexico. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee. Updated March 2019

NHD_MajorWaterbodies are a subset of the largest waterbody features selected from the High Resolution NHD dataset for Washington State. This subset includes only waterbodies that are classified as lake/ponds ,reservoirs, or estuaries and that are > 1 sqKm (10763900 sqft).The National Hydrography Dataset (NHD) is a feature-based database that interconnects and uniquely identifies the stream segments or reaches that make up the nation's surface water drainage system. This high-resolution NHD, generally developed at 1:12,000/1:24,000 scale, adds detail to the original 1:100,000-scale NHD Local resolution NHD is being developed where partners and data exist. The NHD contains reach codes for networked features, flow direction, names, and centerline representations for areal water bodies. Reaches are also defined on waterbodies and the approximate shorelines of the Great Lakes, the Atlantic and Pacific Oceans and the Gulf of Mexico. The NHD also incorporates the National Spatial Data Infrastructure framework criteria established by the Federal Geographic Data Committee.

This data set estimates large-scale wetland distributions and important wetland complexes, including areas of marsh, fen, peatland, and water.