The Seneca River flows 61.6 miles (99.1 km) through the Finger Lakes region of Upstate New York in the United States. The main tributary of the Oswego River – the second-largest river flowing into Lake Ontario – the Seneca drains 3,468 square miles (8,980 km2) in parts of fourteen New York counties. The Seneca flows generally east, and is wide and deep with a gentle gradient. Much of the river has been channelized to form part of the Erie Canal.

The Oswego River is a river in upstate New York in the United States. It is the second-largest river flowing into Lake Ontario. James Fenimore Cooper’s novel The Pathfinder, or The Inland Sea is set in the Oswego River valley.