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Data from US Federal Governments


Base Layers - US       Base Layers - Global/near Global

Biology       Geology

Web Services

(This page is undergoing re-construction.  Please pardon the messy look.)

Base Layers - US

These datasets are downloadable from the Web at no cost. Some of these data have been downloaded and stored at the GIS volume at \\\gisvol\GIS\GISdata\USA (M:\GIS\GISdata\USA).

  • DLG (Digital Line Graphs)
    A variety of features derived from mainly USGS topographic maps
    • Agency: USGS (United States Geological Survey)
    • Sale: Large scale 7.5-minute 1:24,000-, 1:25,000-, 1:63360- maps; intermediate scale 1:100,000; small scale 1:2,000,000
    • Coverage:
      Large scale - conterminous United States, Hawaii, the Virgin Islands (1:24,000), Alaska (1:25,000 or 1:63,360), and Puerto Rico (1:30,000)
      Intermediate scale - 
      conterminous United States and Hawaii
      Small scale - conterminous United States. Alaska, and Hawaii
    • Download Site:
      USGS Geographic Data Download
  • Elevation
    • DEM (Digital Elevation Model) - Replaced by NED
      7.5-minute (1:24,000 or 1:25,000)

      • Agency: USGS (United States Geological Survey)
      • Coverage: All of the U.S. and its territories
      • Resolution: 10 m (1/3 arc-second) for selected quads, 30 m (1 arc-second) for the entire US
    • NED (National Elevation Dataset)
  • Soil
    • SSURGO (Soil Survey Geographic) Database
      1:12,000 to 1:63,360

      • AGENCY: US Department of Agriculture NRCS (Natural Resources Conservation Service)
      • COVERAGE: Conterminous United States, Alaska, Hawaii, and other territories (not completed yet)
        See Data Status to determine if spatial data is available for your area
        USDA Geospatial Data Gateway
        (soil polygons and soil data tables can be downloaded here)

        Natural Resources Conservation Service Soil Data Mart
        (skeleton Access database can be downloaded here)
      • Download Soil Data Viewer to work with the soil database (works stand alone or with ArcGIS 8.3, 9.0, 9.1, 9.2 and 10)
  • Topographic Maps
    • DRG (Digital Raster Graphic, scanned USGS topographic maps)
      7.5-minute map series (1:24,000 or 1:25,000)

      • Agency: USGS (United States Geological Survey)
      • Coverage: conterminous United States, Hawaii, and limited areas of Alaska
      • Download Site:
        USDA Geospatial Data Gateway

Base Layers - Global/near Global

  • Elevation

    Comparison of GTOPO30, SRTM, and ASTERGDEM

    • SRTM (Shuttle Radar Topography Mission)
      • Agency: NASA (U.S. National Aeronautics and Space Administration)
      • Source: Space shuttle radar
      • Coverage: Near global (between 60°N and 56°S)
      • Horizontal Grid Spacing - 1 arc second (about 30 meters) for U.S. and its territories and possessions; 3 arc seconds (about 90 meters) for the world
      • Year Raw Data Acquired: 2000 (version 2 is an improved version over version 1)
      • Download Site:
    • ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer ) Global Digital Elevation Model (ASTERGDEM)
      • Agency: NASA (U.S. National Aeronautics and Space Administration) and Japan's Ministry of Economy, Trade, and Industry (METI)
      • Source: ASTER, a spaceborne earth observing optical instrument
      • Coverage: Near global (between 83°N and 83°S, the entire land surface)
      • Horizontal Grid Spacing - 1 arc second (about 30 meters)
      • Release Year of Version 2: 2011
      • Links to Download Sites: USGS LP DAAC (Land Processes Distributed Active Archive Center)
  • Hydrography
    • Hydro1K
      • Agency: USGS (United States Geological Survey)
      • GTOPO30 (Global 30 Arc-Second Elevation Data Set) derived databases
      • Including hydrologically correct DEM, flow direction, flow accumulation, drainage basins, streams and Compound Topographic Index (CTI, commonly referred to as the Wetness Index)
      • Coverage: Global
      • Horizontal Grid Spacing - 30 arc seconds (about 1 kilometer)
      • Download Site: USGS Earth Resources Observation and Science (EROS) Center


  • The North American Breeding Bird Survey from USGS Patuxent Wildlife Research Center
    As of July 2010, this site contains results from 1996 to 2006.  GIS data, analytical tools and result maps are available.


  • NGMD (National Geologic Map Database) Data Portal
    • Created by The United States Geological Survey (USGS) and the Association of American State Geologists (AASG).  As of June 2010, more than 80,000 maps and reports, by 370 publishers, are accessible.


Web Services

  • USDA (United States Department of Agriculture) NRCS (National Resources Conservation Service) Imagery Map Services:
    Web site:
    ArcGIS Server Service: