Point of Information - Photo - looking east at the Piscataqua River, Maine Crossing the Piscataqua River. The Piscataqua River is a river in the northeastern United States. It is a 12 mi (19 km) long tidal estuary formed by the confluence of the Salmon Falls and Cocheco rivers, and flows southeastward, forming part of the boundary between the U.S. states of New Hampshire and Maine. It empties into the Atlantic Ocean near Portsmouth, New Hampshire, where it forms one of the finest natural harbors in the northeastern United States. The Portsmouth Naval Shipyard is located in the river near its mouth. The drainage basin of the river is approximately 1,495 square miles. The name of the river derives from a Native American word Piscataquanke, meaning 'a great deer place. If you're looking for a great getaway, then head to Maine. You'll find something special in each region. Embark on outdoor adventures like llama trekking, camping, skiing and snowmobiling. Go antiquing in charming villages. Relax on sandy beaches. Encounter amazing wildlife including whales, puffins and the mighty moose. Immerse yourself in Maine's unique culture at our festivals and fairs. And of course, enjoy lobster the Maine way — fresh from the ocean.