Lists and Geographic Codes
- FIPS Codes used in Maryland: A comprehensive list from the Missouri Census Data Center
- ANSI codes: These codes replace previously used FIPS codes.
- FIPS 6-4 County Lookup
- Geographic Boundary Change Notes (Census Bureau)
Shapefiles for Mapping
- TIGER/Line Shapefiles: These files from the Census Bureau cover numerous geographies at both the statewide and county level.
- Cartographic Boundary Files (Census Bureau)
- The National Map (U.S. Geological Survey)
- Geography Network
- Geospatial Data Gateway: Environmental and natural resources data