About the Office


The Loudoun County Office of Mapping and Geographic Information is responsible for maintaining the core components of the county's Geographic Information System (GIS), the computerized mapping system. The office provides internal data, mapping, and analytical services to county agencies and provides services to the public through web-based mapping and at the office's Public Information Counter. The office is responsible for:

  • Assignment of addresses and approval of street names
  • Development and maintenance of web mapping services
  • Development of applications to support county business practices
  • Development and implementation of a Conservation Easement Stewardship Program
  • Distribution of maps and spatial data
  • Management of the Loudoun County Store
  • Management of the spatial database
  • Map and database support for computer aided dispatch (9-1-1), the assessment database, Land Management Information System (permits), and other computer systems
  • Mapping of all changes to parcels and other layers
  • Spatial data development, internal mapping, and analytical services for county agencies
  • Training for county staff

What Is a GIS?

A GIS is a computer system for management, analysis, and display of geographic knowledge. It can produce information that answers specific questions and allows you to share that information with others. By visualizing relationships, connections, and patterns in data, you can make informed decisions and increase efficiency throughout an organization.

GIS Adoption

Loudoun County was an early adopter of GIS, purchasing software from Esri, the GIS software company, in 1986. Today the county operates a distributed GIS that is integrated with the county's other information systems. A distributed system is one for which responsibility for data maintenance and analysis is shared among several departments.


The county's GIS has received numerous awards over the years. View the list (PDF).