You are in the Casco Bay watershed if the water that falls on the ground eventually flows downhill to Casco Bay. This map shows the watershed boundaries.
The following maps of Casco Bay and the watershed can be found on the Publications site by entering Map in the Category or Keyword search box:
Boat Access Sites
Combined Sewer Overflows
Presumpscot River, 20 maps: Corridor; Watershed; Paddling