Web-based GIS: An Overview of Sites and Resources

Lesson developed by Mike Furlough, Geostat Center

Below is a highly selective list of web sites that deliver geographic information, with an emphasis on sites that provide some form of "smart data" or "interactive mapping." These are sites that deliver "information" as opposed to "raw data." This list excludes sites designed primarily to deliver or sell GIS data.

Thesauri and Gazatteers

The Getty Thesaurus of Geographic Names
Part of the Getty "Vocabulary Program" to establish consistent terminology for various areas of study. The TGN is a structured vocabulary containing around 1,000,000 names and other information about places. The TGN includes all continents and nations of the modern political world, as well as historical places. It includes physical features and administrative entities, such as cities and nations. The emphasis in TGN is on places important for art and architecture. No maps, but lattitude/longitude coordinates are included.

GeoNet Names Server
Access to the National Imagery and Mapping Agency's (NIMA) database of foreign geographic feature names. Approximately 20,000 of the database's 3.5 million features are updated monthly with names information approved by the U.S. Board on Geographic Names (US BGN).

GNIS System
Contains information about almost 2 million physical and cultural geographic features in the United States. The Federally recognized name of each feature described in the data base is identified, and references are made to a feature's location by State, county, and geographic coordinates. The GNIS is our Nation's official repository of domestic geographic names information. Especially useful for identifying the topographic map on which a feature appears.
Map Finding Aids

USGS Topographic Map Lists
Search for or list by state the small and large scale topographic maps. Useful for searching by coordinates or for determining if your map is up to date.

National Geologic Map Database
This site can help you find information about maps and related data for: geology, hazards, earth resources, geophysics, geochemistry, geochronology, paleontology, and marine geology. [This database is under construction.]
Maps and "Dumb" Raster Graphics

University of Texas Map Collection
A fair number of scanned maps in the public domain--about 2400--organized for browsing by geographic locations. Includes maps from federal sources such as the CIA, National Park Service. Also includes some historical maps.

Library of Congress American Memory Project: Map Collection
The American Memory Project at the Library of Congress attempts to bring the diverse collections of the LoC to the web. Maps are usually presented using MrSID, a compression tool that enables users to zoom in to very precise and highly detailed views of the map image. Look for links to "Geography" or "Maps" to get to collections of historic Civil War, Panoramic, National Park, and Railroad maps, among other subjects.

Virginia Digital Sanborn Maps Database

Sanborn Maps at the University of Virginia
Sanborn Fire Insurance maps are highly detailed city plans that show building types, materials, and use, which were produced from the 1880s to the 1990s. Most maps were produced during the early parts of the century. The first link provides access to maps of all of Virginia. The Geostat Center here provides access to Charlottesville Maps from 1920, and to an index of streets, addresses and buildings depicted on the maps.

Commercial: Locators


The most widely used on-line GIS service in the world, with as many as 40 million maps generated each month. Locate addresses, find driving directions (use them at your own risk), and obtain a host of other types of geographic information. MapQuest contracts their services to many other web-mappers and address-finders: chances are that the address finder you use is based on MapQuest data.

VISA ATM Locator

Locate VISA ATMs anywhere in the United States, or the world. Not complete--it doesn't include ATMs that are not on the VISA network.

Commercial: Site Selection


A commercial database of homes and dwellings for sale across the US. Search geographically and specify other criteria.

Virginia Scan

Business users can search for available commercial or industrial sites by specifying a number of criteria. Developed by the Virginia Economic Development Partnership using an elaborate GIS system.

City of Tuscon Site Selector

Available commercial and industrial sites in Tuscon, AZ, sponsored by the local government.

Research and Education

Lewis and Clark Education Center

Developed to archive and geographically referenced images, maps, texts and other documents related to the Lewis and Clark expedition.

Arctic Environmental Atlas

Some basic geological and enviornmental map layers for arctic regions.

Planetary Geology USGG Planetary Geology GIS

GIS maps of Mars, Venus and the Moon.

Defense and Intelligence

Bird Avoidance Model

The Bird Avoidance Model helps pilots predict where bird strikes could occur based on geographic location and time of year.
Law Enforcement

Illinois State Police Interactive Mapping

City of Sacramento -- Major Crimes
http://maps.cityofsacramento.org/   note: Crime map not always available

Two sites created to keep citizens informed of crime in their area. BUT--what do these maps really tell you?

Local Government Services

City of Sacramento -- Business

Chatham County NC -- Parcel Database

Chatham County makes it's parcel and tax database available on the web, enabling citizens to research potential purchases online. Most cities make this public information available only in their offices.

Prince William County Mapper

Prince William County, VA provides this site as a general reference map for public services.

Traffic Routing, Directions, Analysis

Routing, Directions, Traffic Inside Illinois: RouteMAP Illinois

Directions, locations, and travel conditions throughout the state of Illinois.

UVA/VDOT Smart Travel Lab

A joint project of the UVA Department of Civil Engineering and the Virginia Transportation Research Council. Researchers in the lab are developing prototype systems and applications that promise to improve the effectiveness of Intelligent Transporation Systems (ITS). Includes continually update maps of traffic volume in the Hampton Roads area, as well as an animation showing the patterns of volume over the previous 24-hour period.


National Atlas of the United States

The USGS published it's National Atlas of the United States in 1970, featuring hundreds of beautifully drawn thematic maps of the county. Rather than update the print version, the USGS has chosen to produce an online interactive version. There are a number of interactive and animated maps available. While users can get some interesting maps here, a comparison of this site and the original print atlas will demonstrate how far online mapping has to go to match the possiblities of print. NOTE: Users can obtain GIS data used to generate the atlas from this site.

US Census: American FactFinder

The US Census has now released initial population results from the 2000 Census through this website. Using American FactFinder, users can retrieve tables and generate maps of the US by state, county, city, and smaller areas.
Emergency Services and Public Health

Wildland Fire Support

Locate active wildfires in the United States.
ESRI/FEMA Online Hazard Mapping

Public service, but driven by a commercial enterprise eager to spread the gospel of its own software. Developed by ESRI--the makers of ArcView & ArcInfo--to highlight their web-mapping software and products. An interesting site, nonetheless: make hazard maps with FEMA information and data by your zip code, hometown, or congressional district. Note the disclaimers.

Pennsylvania West Nile Tracker

National Atlas Virus Tracker

Two sites to track occurences of West Nile Virus in the United States.
For Further Information: GIS News and Resource Sites





Sites offering news, links, information, job listings, and sometimes spatial data.


A range of industry- or region-specific GIS magazines online, such as GeoWorld, GeoEurope and Business GeoGraphics.


ESRI's online version of their magazine, including tutorials, articles about GIS in the real world and information about software and conferences.


What it says: GIS related jobs.