This dataset consists of land areas that are run and maintained by U.S. Governmental authorities. These files were created for planning purposes and should not be used as a definitive source of mapped data for any of the associated types of land ownership. There have been intentional omissions due to sensitive data types and in some cases, the source documents cannot be considered complete.

The Federal Lands data layer was updated to show the most current known lands presently owned by the Federal Government. The sources of the updates came from several sources (the US Park Service, Maryland Department of Planning, MD Property View, ed. 2005, etc.). Ownership status was checked over parcel boundaries and known property records for completeness and accuracy. US Postal properties were not included in this data set.