All data are stored in a database with private and public sections. The Private area is secure behind the State firewall, accessible to only those on the State network. The public area is available to all users. DTI works with both public and private owners to provide access to their data and to ensure the most current data are available.

FirstMap is hosting a variety of datasets via map, feature and image services, organized by ISO Categories.

Geocoder Service

Geocoding services allow users to find discrete point locations from their address data. These point locations are calculated based on a physical street address. The FirstMap geocoder is a composite geocoding service. Geocoder Service

Map Services

  • Map Services provide basic access to the underlying data. Users have the ability to identify, query and display Map Services within ArcMap. The features in a Map Service are symbolized and cannot be changed; however all features are displayed.
  • Feature Services provide expanded access to the underlying data. Because of this you can symbolize Feature services within your ArcMap project. Because Feature Services limit the number of features returned to the user not all of the services in FirstMap have Feature Access enabled.

If you have any difficulty finding a data layer, have any questions, or want to contribute data, please email the FirstMap team.

Aerial Imagery Services

Delaware has a diverse range of imagery going back as far as 1937. Complete metadata and specifications are in our Imagery Metadata document.

  • Image Services provide access to raster data. These image services can be cached to provide excellent performance or dynamic to provide flexibility of use.

Open Data

This site provides the ability to search, filter, and download Delaware's publicly available spatial data in a variety of formats including shapefile and KML.

For additional information, please email us at

end page