Frederick County, MD

Maryland County

County seat is the City of Frederick. The county was named for Frederick Calvert (1731-1771), the sixth and last Lord Baltimore. Principal towns are Emmitsburg, Frederick, and Thurmont. The county extends from the Pennsylvania border at the north to the Potomac River at the south. The western boundary is South Mountain; to the east are Carroll and Montgomery counties.

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Frederick County, MD

Maryland County

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The Lower Potomac
The Potomac Estuary
Mount Vernon to Anacostia River
Mall Area
Georgetown to Great Falls
Potomac Piedmont
Upper Potomac
The North Branch

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Monitoring Sites
Bridges and Ferries
Cruises and Charters

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