Map of Maryland County Boundaries


Maryland County Boundaries Shapefile (download)

Source: Chesapeake Bay ​Program


  • This polygon shapefile represents the geographic boundaries of the 23 Maryland counties and Baltimore City. The counties in this polygon file relate to TMDLs and WLAs in the applicable query via county name.

Please direct questions or comments concerning Maryland's TMDL Program to at (410) 537-3818.​​