Mohawk River, the main tributary of the Hudson River, in east-central New York. From its source near Rome it flows about 140 miles (225 km) southeastward past Utica, Amsterdam, and Schenectady to meet the Hudson near Cohoes. The Mohawk Valley, one of the main passages through the Appalachians, is a fertile lowland between the Adirondack Mountains and the Allegheny Plateau. It has been a major trade and transportation route since pioneer days. Paralleling the river is part of the old Erie Canal, completed in 1825 and now the main waterway of the New York State Barge Canal. The river was named after the Mohawk Indians.