The Cal-Atlas site facilitates the coordinated effort by California government agencies, partners and stakeholders to make available public data. This site also features the California Environmental Information Clearinghouse Catalog, a collection of California maps, and the opportunity to contribute data to the site.
The EPA's Envirofacts site has data available on subjects related to air and water quality, toxins and waste products, and permit compliance.
The EPA’s National Geospatial Program makes data available both through program specific databases as well as by EPA region.
ArcGIS Online Services are integrated with ArcGIS and gives the user immediate access to cartographically designed, seamless basemaps to which the user can easily add his/her own data. There are standard and premium services, 2D maps & 3D globes, which can be accessed over the web.
The GeoCommunity hosts the GIS Data Depot where you can download or purchase data at both state and county levels including DEM’s, DRG’s, and DOQQ’s.
The GeoCommons Finder site is a user generated GIS data community site containing an enormous variety of data sets. Data is available as shapefiles, spreadsheets, and KML.
Geodata.gov, also known as the Geospatial One-Stop (GOS), serves as a public gateway for improving access to geospatial information and data under the Geospatial One-Stop E-Government initiative. The portal is a catalog of geospatial information containing thousands of metadata records and links to live maps, features, and catalog services, downloadable data sets, images, clearinghouses, map files, and more.
The Geography Network, hosted by ESRI, is a global network of geographic information users and providers. Data can be searched for by topic or geographic extent.
The Landsat Program is a series of Earth-observing satellite missions jointly managed by NASA and the U.S. Geological Survey. The GeoCover 30m Landsat image mosaics are delivered both as uncompressed color
imagery in GeoTIFF format and as compressed color imagery in MrSIDTM file format. The data are delivered as 24-bit color uncompressed GeoTIFF files and as 24-bit color MrSID compressed files.
NASA's Global Change Master Directory (GCMD) allows users to locate and obtain access to Earth science data sets and services relevant to global change and Earth science research. The GCMD database holds more than 25,000 descriptions of Earth science data sets and services covering all aspects of Earth and environmental sciences. You can use the search box or select from the available keywords to search for data and services.
The Research and Innovative Technology Administration (RITA) coordinates the U.S. Department of Transportation's (DOT) research programs and provides access to data by mode (of transportation) and by subject. Subjects include safety, infrastructure, energy, national safety, and economic data.
SPOT Satellite Imagery is available, for a fee, as low as 2.5m resolution.
The BLM maintains and makes available its GIS data by individual state. Most states post land use and land management data, designated boundary files, some recreation data sets, and many others depending upon the state site. They also have a public FTP site (ftp://ftp.blm.gov/pub/) for data download.
The U.S. Census TIGER/Line®Shapefiles are spatial extracts from the Census Bureau's MAF/TIGER database, containing features such as roads, railroads, rivers, as well as legal and statistical geographic areas. The files do not include demographic data, but they contain geographic entity codes that can be linked to the Census Bureau’s demographic data, available on American FactFinder.
U.S. Fish and Wildlife Service GIS Home Page provides data referenced at various scales ranging from 1:12,000 to 1:500,000. The data is organized by state with source, theme, spatial coverage, scale, metadata and data link information available for each item.
The U.S. Fish and Wildlife Service is the principal Federal agency that provides information to the public on the extent and status of the Nation's wetlands. The agency has developed a series of topical maps to show wetlands and deepwater habitats. This geospatial information is used by Federal, State, and local agencies, academic institutions, and private industry for management, research, policy development, education and planning activities. Digital data can be viewed and downloaded by user extent using a Wetlands Mapper website or by quads (24k or 100k for lower 48 states, various for other areas) using the Wetlands Data Extraction Tool website. Data available: shapefiles containing polygons, metadata, and historic map reports; raster scans of hardcopy wetland maps (cannot be downloaded but can be viewed and snapshots taken); Web Map Services; Google Earth KMZ files.
The Digital Line Graphs (DLGs) are essentially the lines you see on the USGS topographic maps. The digital data is available at both 1:24,000 and 1:100,000 scales. The files include:
Public Land Survey System (PLSS) lines,
State, county, city, and other national and State lands such as forests and parks,
Roads and trails, railroads, pipelines, and transmission lines,
Flowing water, standing water, and wetlands
Contours and supplementary spot elevations
Glacial moraine, lava, sand, and gravel
Horizontal and vertical monuments (third order or better)
Cultural features, such as buildings, not collected in other data categories
Vegetative surface cover
The purpose of the National Center for Earth Resources Observation & Science (EROS) Othoimagery website is to provide instant access to The National Map Orthoimagery. The Orthoimagery category is one of the framework layers for The National Map. Imagery can be used as a base layer for updating or deriving additional geographic information, such as transportation networks, hydrographic features, elevation, and land cover. The orthoimagery featured in the website includes High Resolution Orthoimagery, Landsat 7 Mosaics, and seamless Digital Orthophoto Quarter Quadrangles (DOQQ).
The USGS National Biological Information Infrastructure Gap Analysis Program provides data and maps related to landcover, stewardship or predicted species distribution data. Data is available at the regional and state level.
The USGS Land Cover Institute posts links to a huge amount of land cover/land use sites, for the US and around the globe. Each data link is nicely documented as to content, scale, and cost.
The National Aerial Photography Program (NAPP) provides a standardized set of cloud-free aerial photographs covering the conterminous United States over 5 to 7 year cycles. The program began in 1987 and ended in 2004. The photographs were acquired from an altitude of 20,000 feet and are available in black & white (B/W) or color-infrared (CIR), depending on location and date. Each photo is centered on one-quarter section of a 7.5-minute USGS quadrangle and covers an area about 5.5 x 5.5 miles. The file sizes are about 15 megabytes for black and white images and 40 megabytes for color images. The files are stored in TIFF format. The medium-resolution files are created at about 400 dpi. Files can be downloaded free of charge.
This index lists all of the map layers currently contained in nationalatlas.gov™, by broad subject categories that correspond to the chapters of the National Atlas. Data categories include Agriculture, Environment, People, Biology, Geology, Transportation, Boundaries, History, Water, Climate, and Map Reference. Most data is available as shapefiles.
The USGS National Elevation Dataset has been developed by merging the highest-resolution, best quality elevation data available across the United States into a seamless raster format. Data is selected and downloaded from a map selection rectangle, map template, or map coordinates.
The National Hydrography Dataset is a comprehensive set of digital spatial data that contains information about surface water features such as lakes, ponds, streams, rivers, springs and wells. Data is available through an interactive viewer to select subbasin units or pre-staged subregion units.
On the National Park Service’s Data and Information Clearinghouse you can search for data by category or NPS unit. There is also an Interactive Map Center for viewing park boundaries and related information, and an assortment of other GIS resources.