Four Major Maine Rivers Flow North Due to Geological Slopes
Contrary to most rivers in Maine that flow towards the Atlantic Ocean, four significant rivers in the northern part of the state—the Upper St. John, Allagash, Fish, and Aroostook—flow northward. These four rivers are integral components of the St. John River basin, which ultimately drains into New Brunswick, Canada, and then into the Bay of Fundy. The primary reason for this unusual flow direction is the topography of northern Maine; the land in this region slopes towards the St. John River basin rather than towards the major south-flowing rivers of Maine. A distinct drainage divide separates these two systems, ensuring that water falling on the northern side flows towards the St. John, while water on the southern side flows towards rivers like the Penobscot and Kennebec, eventually reaching the Atlantic. The Allagash River exemplifies this, flowing approximately 62 miles north from Churchill Dam to join the St. John River, descending over 300 feet in the process. 
