Manuscript map #82, entited "Plan of the county of Cumberland, Casco Bay from New Meadow & c. rivers 1773." This early map shows a plan of the area including the Saco River, showing Sebago Lake, the Kennebec and Androscoggin Rivers. The naming of this area as Cumberland County refers to the 1773 boundaries of Cumberland County, and not the present-day county boundaries.

Towns included on this map are Falmouth (Portland), Scarborough, Pepperrellborough (Saco), Buxton, Pearsontown (Standish), New Boston (Gray), New Gloucester, North Yarmouth, Cape Elizabeth, Brunswick, Royalston (Durham), Georgetown, Topsham, Gorham, and Arrowsic.