The Piscataqua River, named by the area’s original Abenaki inhabitants, is a 12-mile-long river forming the boundary of the U.S. states of New Hampshire and Maine from its origin at the confluence of the Salmon Falls River and Cochecho River. The drainage basin of the river is approximately 1,495 square miles, including the subwatersheds of the Great Works River and the five rivers flowing into Great Bay: the Bellamy, Oyster, Lamprey, Squamscott, and Winnicut.
The river runs southeastward, with New Hampshire to the south and west and Maine to the north and east, and empties into the Gulf of Maine east of Portsmouth, New Hampshire. The last 6 miles (10 km) before the sea are known as Portsmouth Harbor. The historical cities and towns of Portsmouth, New Castle, Newington, Kittery and Eliot are located around the harbor.
Source: Piscataqua River