See http://viewer.nationalmap.gov/help for assistance with The National Map viewer, services, or metadata.

The USGS National Hydrography Dataset (NHD) service from The National Map (TNM) is a comprehensive set of digital spatial data that encodes information about naturally occurring and constructed bodies of surface water (lakes, ponds, and reservoirs), paths through which water flows (canals, ditches, streams, and rivers), and related entities such as point features (springs, wells, stream gages, and dams). The information encoded about these features includes classification and other characteristics, delineation, geographic name, position and related measures, a "reach code" through which other information can be related to the NHD, and the direction of water flow. The network of reach codes delineating water and transported material flow allows users to trace movement in upstream and downstream directions. In addition to this geographic information, the dataset contains metadata that supports the exchange of future updates and improvements to the data. The NHD is available nationwide in two seamless datasets, one based on 1:24,000-scale maps and referred to as high resolution NHD, and the other based on 1:100,000-scale maps and referred to as medium resolution NHD. Additional selected areas in the United States are available based on larger scales, such as 1:5,000-scale or greater, and referred to as local resolution NHD. The NHD from The National Map supports many applications, such as making maps, geocoding observations, flow modeling, data maintenance, and stewardship. For additional information on the NHD, go to http://nhd.usgs.gov/index.html. The Watershed Boundary Dataset (WBD) is a companion dataset to the NHD. It defines the perimeter of drainage areas formed by the terrain and other landscape characteristics. The drainage areas are nested within each other so that a large drainage area, such as the Upper Mississippi River, will be composed of multiple smaller drainage areas, such as the Wisconsin River. Each of these smaller areas can further be subdivided into smaller and smaller drainage areas. The WBD uses six different levels in this hierarchy, with the smallest averaging about 30,000 acres. The WBD is made up of polygons nested into six levels of data respectively defined by Regions, Subregions, Basins, Subbasins, Watersheds, and Subwatersheds. For additional information on the WBD, go to http://nhd.usgs.gov/wbd.html. The National Map hydrography data is commonly combined with other data themes, such as boundaries, elevation, structures, and transportation, to produce general reference base maps. The National Map download client allows free downloads of public domain NHD and WBD data in either Esri File Geodatabase or Shapefile formats.

The USGS Map Indices service from The National Map (TNM) consists of 1x1 Degree, 30x60 Minute (100K), 15 Minute (63K), 7.5 Minute (24K), and 3.75 Minute grid polygons used in The National Map viewer for reference and to download data. At 1:24,000-scale (24K), the standard map size is 7.5 minutes of latitude by 7.5 minutes of longitude. At 1:100,000-scale (100K), the standard map size is 30 minutes of latitude by 60 minutes of longitude. The National Map viewer allows free download of public domain USGS map indices data in Esri File Geodatabase format.

<DIV STYLE="text-align:Left;"><DIV><P><SPAN>USGS developed The National Map Gazetteer as the federal and national standard (ANSI INCITS 446-2008) for geographic nomenclature based on the Geographic Names Information System (GNIS). The National Map Gazetteer contains information about physical and cultural geographic features, geographic areas, and locational entities that are generally recognizable and locatable by name (have achieved some landmark status) and are of interest to any level of government or to the public for any purpose that would lead to the representation of the feature in printed or electronic products and/or geographic information systems. The dataset includes features of all types in the United States, its associated areas, and Antarctica, current and historical, but not including roads and highways. The dataset holds the federally recognized name of each feature and defines the feature location by state, county, USGS topographic map, and geographic coordinates. Other attributes include names or spellings other than the official name, feature classification, and historical and descriptive information. The dataset assigns a unique, permanent feature identifier, the Feature ID, as a standard Federal key for accessing, integrating, or reconciling feature data from multiple datasets. This dataset is a flat model, establishing no relationships between features, such as hierarchical, spatial, jurisdictional, organizational, administrative, or in any other manner. As an integral part of The National Map, the Gazetteer collects data from a broad program of partnerships with federal, state, and local government agencies and other authorized contributors. The Gazetteer provides data to all levels of government, to the public, and to numerous applications through a web query site, web map and feature services, file download services, and customized files upon request. The National Map viewer allows free downloads of public domain geographic names data by state in a pipe-delimited text format. For additional information, go to http://nationalmap.gov/gnis.html.</SPAN></P></DIV></DIV>

The USGS 3D Elevation Program (3DEP) Index service from The National Map shows two general categories of downloadable elevation data: (1) digital elevation model (DEM) datasets at standardized horizontal resolutions, and (2) elevation source data including that used to produce standard DEMs, and additional datasets derived from ifsar in Alaska only. Distributable DEM products include: 2 arc-second (in Alaska only); 1 arc-second; 1/3 arc-second; 1/9 arc-second; 5 meter (in Alaska only); and 1 meter. The 2-, 1-, and 1/3-arc-second products are staged for download in 1x1 degree tiles in ArcGrid, GridFloat, or IMG formats, while 1/9 arc-second products are staged in 15x15 minute tiles in IMG format only. The 5-meter products are staged for download in ArcGrid only as a single mosaicked raster to each project extent. The 1-meter products are staged in 10,000x10,000 meter tiles in IMG format only. Distributable elevation source data include: lidar point clouds (LPC) in LAS format for various parts of the U.S., and ifsar-derived digital surface models (DSM) and orthorectified radar images (ORI) in TIFF format in Alaska only. For additional information on the 3DEP, go to http://nationalmap.gov/3DEP/index.html.

The USGS Transportation service from The National Map (TNM) is based on TIGER/Line data provided through U.S. Census Bureau and road data from U.S. Forest Service. Some of the TIGER/Line data includes limited corrections done by USGS. Transportation data consists of roads, railroads, trails, airports, and other features associated with the transport of people or commerce. The data include the name or route designator, classification, and location. Transportation data support general mapping and geographic information system technology analysis for applications such as traffic safety, congestion mitigation, disaster planning, and emergency response. The National Map transportation data is commonly combined with other data themes, such as boundaries, elevation, hydrography, and structures, to produce general reference base maps. The National Map download client allows free downloads of public domain transportation data in either Esri File Geodatabase or Shapefile formats. For additional information on the transportation data model, go to http://nationalmap.gov/transport.html.