The Saco River is a tributary of the Piscataqua River in southern Maine. It rises at the confluence of its two branches, the North Branch and South Branch, which rise in northeastern New Hampshire and flow south into Coos County in southwestern Maine. The river flows for 200 miles from its headwaters to its mouth on the Atlantic Ocean near Biddeford Pool. The Saco River has been used as an important transportation corridor since Native Americans first discovered it centuries ago. Today, people are still using this natural waterway to get to their destinations!