largest tributary of the Hudson River, east-central New York, U.S. Draining 3,412 square miles (8,837 square km), the Mohawk forms in Oneida county at the junction of its East and West branches. It then flows 140 miles (225 km) south and east past Rome, Utica, Amsterdam, and Schenectady, joining the Hudson at Waterford, north of Troy. A 117-mile (188-km) section of the Erie Canal (now part of the New York State Canal System) that parallels the river from Rome to its mouth has been largely abandoned and is now replaced by the river itself, whose channel was deepened and straightened. The Mohawk Valley (Mohawk Trail) was the historic route through the Appalachian Mountains into the Great Lakes region and served westbound pioneers. The Five Nations of the Iroquois Confederacy (including the Mohawk) lived in the fertile valley, which was a major battleground during the French and Indian War and the American Revolution.