Cobscook Bay in Pembroke, located about 1.5 miles west of Eastport, is an indentation of the Maine coast’s northeastern end. The bay is used by fishing and recreational boats.

Corps’ work in Cobscook Bay, completed in 1866; involved removing rocks from an area between Mahar Point at Leighton Neck and the western end of Falls Island. The rocks had obstructed navigation in the channel leading to Denny’s Bay.