This guide provides a roadmap to U.S. sources for maps and geographic data and support for the EnviroSource.com category Maps/Geographic Data.

If you are searching for maps or geographic data, the number of resources available are endless. This can sometimes lead to confusion over what is out there, who is providing it and how to get it. While it may seem difficult and time-consuming to navigate through this maze, there are some general directions in which to head.

There are several government sources of geographic data. The US Geological Survey (USGS) is the agency primarily responsible for collecting, analyzing, interpreting and distributing data on mineral, land and water resources. USGS Information Services (also known as the Map Store) located in Denver, CO carries the largest selection of USGS data products and can answer technical and product questions. The USGS distributes its own information as well as other agencies' such as the Bureau of Land Management (BLM), the National Imagery and Mapping Agency (NIMA) and the Bureau of Mines. Information Services is the main contact if you are seeking USGS geographic data.

The Earth Science Information Centers (ESICs), with nine locations throughout the US (Sioux Falls, SD; Reston, VA; Rolla, MO; Denver, CO; Menlo Park, CA; Anchorage, AK; Salt Lake City, UT; Spokane, WA; and Washington DC), distribute USGS data products as well. While the ESICs tend to have regional and specialty emphasis, they are distributors of all USGS products. For example, the Earth Resources Observation Systems EROS Data Center (EDC) located in Sioux Falls, SD specializes in digital data and satellite imagery. The EDC features an online Earth Explorer where users can search for geographic data by subject area, read short descriptions about products, place online orders and in some cases download data. But the Sioux Falls ESIC can provide assess to all USGS products as well. The ESIC located in Reston, VA is considered the central ESIC.

There are five USGS Regional Mapping Centers (Sioux Falls, SD; Reston, VA; Rolla, MO; Denver, CO; and Menlo Park, CA) responsible for managing the programs and activities within the scope of the National Mapping Program. Several of these facilities provide direct data and information access and retrieval via the Internet. Most Regional Mapping Centers are located and work in conjunction with an ESIC. The mapping centers create the geographic data products and the ESICs distribute them.

There are many other government agencies which produce and provide geographic data. For example, the National Aeronautics and Space Administration's (NASA) Earth Observing and Information System (EOSDIS) is supported by several Distributed Active Archive Centers (DAACs). Each DAAC has a particular discipline including oceanography, snow and ice, land processes and atmospheric dynamics. Additional agencies supporting geographic data include the National Oceanic and Atmospheric Administration (NOAA), the US Army Corp of Engineers (USACE) and the Department of Agriculture. Some smaller agencies and centers support data such as the National Earthquake Information Center, the National Water Information Center and the Tennessee Valley Authority. Contact other federal agencies to find out if they offer any geographic data. (See the EnviroSource.com category Federal/National - Agencies)

Some products are available from the central government printing and distribution organizations - the National Technical Information Service (NTIS) and the Government Printing Office (GPO). Many states and universities distribute data as well. (See the EnviroSource.com categories Hotlines/Clearinghouses, State/Regional - Agencies, and Universities/Colleges).

USGS Commercial Dealers are retail map outlets whose services include faster access to all USGS products, custom mapping, GIS technology and environmental site data.

The Internet may be the best resource for finding the exact geographic data products to meet your needs. More and more commercial providers of data have Web pages describing their products and services. There are several online databases and clearinghouses for geographic and geospatial information. The USGS has an extensive network of Web pages filled with source contact information and available products. The Federal Geographic Data Committee (FGDC) maintains a Web site with links to clearinghouses, sources of data, and a Manual of Federal Geographic Data Products. In addition, much of the data on the Internet can be downloaded for free. (See the EnviroSource.com Subject Guide titled Databases/Online Systems Guide for information about downloading software from the Internet).