The Seneca River in Central New York flows from west to east, from Seneca Lake, though the Montezuma Marsh at the north end of Cayuga Lake to the Seneca's confluence with the Oneida and Oswego rivers at the Three Rivers area north of Syracuse. The Oswego empties the water of the other two rivers into Lake Ontario. The Erie Canal follows some of the length of the Seneca, and the Cayuga-Seneca Canal includes the upper part of the river.