Online nationwide United States Spatial Data

ASTER & MODIS

• LP DAAC Data Pool: Hosts ASTER data covering the US and MODIS data covering the globe for free
• ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is an imaging instrument flying on Terra, a satellite launched in December 1999 as part of NASA's Earth Observing System (EOS). ASTER is being used to obtain detailed maps of land surface temperature, reflectance and elevation.
• MODIS (Moderate Resolution Imaging Spectroradiometer) is a key instrument aboard the Terra (EOS AM) and Aqua (EOS PM) satellites. Terra's orbit around the Earth is timed so that it passes from north to south across the equator in the morning, while Aqua passes south to north over the equator in the afternoon. Terra MODIS and Aqua MODIS are viewing the entire Earth's surface every 1 to 2 days, acquiring data in 36 spectral bands, or groups of wavelengths (see MODIS Technical Specifications). These data will improve our understanding of global dynamics and processes occurring on the land, in the oceans, and in the lower atmosphere. MODIS is playing a vital role in the development of validated, global, interactive Earth system models able to predict global change accurately enough to assist policy makers in making sound decisions concerning the protection of our environment.

Environmental Protection Agency (EPA)

• EPA Geospatial Data Download Service
• Toxic Release Inventory (TRI) Program : A web mapping site that includes the ability to accurately assess latitude and longitude to the building level using interactive maps and aerial photography.
• National-Scale Air Toxics Assesment: Emission density maps, data tables, data summaries, and data sources

National Oceanic and Atmospheric Administration

• National Climatic Data Center (NCDC): Climate maps of the US
• NOAA Electronic Navigational Charts: Interactive online viewer
• NOAA Navigational Charts: Scanned nautical charts

U.S. Geological Survey (USGS)

• GAP, USGS National Biological Information Infrastructure: A scientific means for assessing to what extent native animal and plant species are being protected.
• Major USGS Geoscience Databases and Science Programs
• National Elevation Dataset: Downloadable from Seamless and The National Map
• National Geologic Map Database
• National Geologic Map Database Portal
• National Hydrography Dataset (NHD)
• National Land Cover Characterization Project: Downloadable from Seamless and The National Map. Also see NLCD Land Cover Class Definitions
• The National Map
• Seamless Data Warehouse
• Shuttle Radar Topography Mission
• USGS Geographic Data Download: provides 1:2k DEM, 1:24K DEM, 30m NED, 1:2m DLG, 1:24K DLG, LULC, NLCD, and NHD. These datasets can often be found from other websites in formats that may be easier to work with
• USGS Maps and GIS Information of Water Resources
• USGS Topographic Map Index (MapFinder) from Digital Data Services Inc: Navigate and view in Google Earth or download as a tif image

Other Governmental Sources

• Agricultural Resources and Environmental Indicators (AREI) Database and Mapping Tool: Combines the Economic Research Service of the USDA with internet mapping technology. One can map farm output, information about farm workers, inventory, and sales for crops and livestock, and much more. Tables can be viewed and downloaded.
• Binational Border Transportation Planning & Program Process: Includes downloadable base layers for Mexico's transportation system in ESRI data format.
• Bureau of Transportation Statistics Mapping Center
• FEMA Flood Insurance Rate Maps (FIRM): View and download flood maps in PDF or TIF format. Searching can be done by address or community. FIRM maps for the US are available in GIS format in the GIS lab: call number G3701.C32 1998.U5
• Formerly Used Defense Sites (FUDS) Public GIS: The Department of Defense (DoD) is responsible for environmental restoration of properties that were formerly owned by, leased to, or otherwise possessed by the United States and under the jurisdiction of the Secretary of Defense. Such properties are known as Formerly Used Defense Sites (FUDS). The Army is the executive agent for the program and the U.S. Army Corps of Engineers is the organization that manages and directs the program's administration.
• GeoCommunicator: Provides searching, accessing and dynamic mapping of US government data. Also see documentation
• Geodata.gov
• Maps in American Factfinder, US Census Bureau
• National Agricultural Statistics Service: Part of the US Department of Agriculture. It provides maps, charts, and historical data about crops, livestock, economics, and research. Historical data goes back to 1970. It also includes an agricultural chemical use database that allows the user to map a specific crop and the amount of pesticides used to treat it.
• The National Atlas
• National Center for Health Statistics - GIS and Public Health
• National Geospatial Data Clearinghouse: Federal Geographic Data Committee (FGDC) maintains access to collection of over 100 spatial data servers that have digital geographic data primarily for use in GIS, image processing systems, and other modeling software
• National Hurricane Center: Hurricane GIS data for the US, often going back to 2008.
• National Wetlands Inventory: Also see Wetland and Deepwater Habitat Classification
• Soil Data Mart, United States Department of Agriculture, Natural Resources Conservation Service
• US Department of Housing and Urban Development (HUD) Local Level Data: Includes foreclosure data
• US Department of Energy, Wind & Hydropower Technologies Program: Wind resource maps
• US Energy Information Administration (EIA) - Maps: Exploration, resources, reserves and production
• US Fish and Wildlife Service Geospatial Services: Various environmental and conservation datasets are available for the US (hydrology, habitats, ecosystems, etc.)

Other Data Sources

• International Association of Assessing Officers: Assessor appraisal websites for the US
• Microsoft Terraserver: A large catalog of aerial photographs and remotely sensed imagery. This is not a comprehensive site. It does have some data for outside of the US.
• Microsoft Research Maps: Topographic maps, digital orthophoto quads (DOQ), and satellite images of the United States.
• National Historical Geographic Information System (NHGIS): Over 12,000 aggregate US Census tables and 430 GIS shapefiles spanning the entire United States from 1790 to 2010, available for download on a free website.
• National Renewable Energy Lab (NREL): Dynamic Maps, GIS Data and Analysis Tools
• National Park Service GIS
• Oak Ridge National Laboratory, CTA Transportation Networks: Geographically-based representations of North American transportation infrastructure suitable for individual modal or multimodal studies. The major components of this data system are analytic link-node networks designed primarily to support routing, traffic, investment, and reliability applications. However, their geographic bases also allow cartographic applications and the association of auxiliary environmental or economic data that are geolocated.
• State Online Atlases: A list of links hosted by Western Illinois University
• STATSGO: State by state soil data from the USDA/NRCS as Arc/INFO export format files
• WebGIS: Offers free downloads of terrain data, LULC, and DLGs in shapefile and other formats
• Woods Hole Science Center - Information Archives