The Cochecho River (incorrectly Cocheco River) is a tributary of the Piscataqua River, long, 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. Significant tributaries include the Ela River, the Mad River, and the Isinglass River. History of the name Cochecho is an Abenaki word meaning "rapid foaming water," referring to Cochecho Falls in downtown Dover. Settlers adopted the name for both the river and their principal settlement, Cochecho village. In 1642, Richard Waldron was granted water privileges at Cochecho Falls, moving there from Dover Point to build a sawmill and gristmill. During the Industrial Revolution, these industries would be supplanted by cotton textile mills. In 1827, the Cocheco Manufacturing Company was founded, and its brick buildings would come to dominate the riverfront. But as 19th-century historian Caroline Harwood Garland writes, "By an error of the engrossing clerk in the act of incorporation, the old Indian word, Cochecho, became Cocheco." Another early historian, Alonzo Hall Quint, laments the error: "The chief fault of the present Company is their barbarous spelling of 'Cocheco' instead of 'Cochecho,' for which no possible excuse exists." In an 1851 essay written for the Dover Enquirer, Quint records the history of the Cochecho River's name: It has been ill-treated in a most serious manner. Every person seems to have felt himself authorized to manage its orthography in any way he chose; hence all sorts of ways of spelling it have prevailed. The first record in which we meet the name is in 1642, and in that the name is spelt CUTTCHECHOE, the pronunciation of which is evident. In 1648 it is spelt COCHCHECHOE and is so pronounced for many years. In 1650 COCHECHAE is met with for once, and the pronunciation of this manner of spelling was that usually followed about 1670. In later times the pronunciation of the last syllable had reverted to the original form, that of the first and second remaining as it was so that Cochecho became the name; this is seen to be almost the exact original pronunciation and has been well settled for years. The spelling KECHEACHY was used occasionally a few years