The Cochecho River or Cocheco River is a tributary of the Piscataqua River, 38.3 miles (61.6 km) long,[1] in the U.S. state of New Hampshire. It rises in northern Strafford County and runs southeastward, through the town of Farmington and the cities of Rochester and Dover, where it provides hydroelectric power. Below the center of Dover, the river is tidal and joins the Salmon Falls River at the Maine border to form the Piscataqua.
Cochecho is an Abenaki word believed to mean "rapid foaming water", referring to the river's falls in today's downtown Dover. Settlers adopted the name for the entire river. It is believed that the shift from Cochecho to Cocheco can be traced to a clerical error at the 1827 incorporation of the defunct Cocheco Manufacturing Company[2]. The spelling "Cocheco" was adopted as the official name of the river in a 1911 decision by the United States Board on Geographic Names. The river has also been known as the Dover River.[3]
Significant tributaries include the Ela River, the Mad River, and the Isinglass River.