- The State of Maryland has created and collected an entire suite of interactive maps. These can be found through the online portal called MDiMap
- The Maryland Department of Natural Resources provides several interactive maps.
- Interactive Soil maps can be found at the USDA's Web Soil Survey.
- The State of Maryland Department of Information Technology maintains a statewide GIS Data Catalog with downloadable data and geodata services.
- The Department of Transportation maintains an Open Data Portal with downloadable data and geodata services.
- The Maryland Department of Planning makes various census and planning layers available for download.
- Wetlands data can be viewed and downloaded from the U.S. Fish & Wildlife Services National Wetlands Inventory.
- Download Soils data from the Natural Resources Conservation Service.
- Tax records for Calvert County can be accessed online from the Maryland Department of Assessments & Taxation.
- Deed and mortgage records can be accessed online from the Maryland State Archives. A free account must be created first.
- Plats can be obtained online from the Maryland State Archives.
- Historic USGS Quad maps of the county and surrounding areas can be found at this collaborative site sponsored by the University of New Hampshire. We have provided the local USGS Quad maps on our Historic Maps page.
- The David Rumsey online map collection boasts an impressive selection of historic maps, many of which cover Maryland and the surrounding areas.
- In conjunction with the Department of Community Planning & Building, we have created an interactive map for the historic "Mackall Road Route" driving tour.
- The surrounding counties of Anne Arundel, Charles, Prince Georges, and St. Mary's each have their own GIS pages.
- The Maryland State Geographic Information Committee (MSGIC) serves as a focal point for
coordinationof statewide GIS activities.
- The Ramona GIS Inventory is a national database which many Maryland jurisdictions are using to catalog their GIS data holdings.
- Obtain official FEMA flood maps from FEMA's Map Service Center.
- The Maryland Department of the Environment maintains a GIS Resources web page.
- The Eastern Shore Regional GIS Cooperative offers maps and data that pertain to the state as a whole and may be of interest.