 Its principal tributary from the north is the Chenango River.The Tioga River enters New York from Pennsylvania near the eastern border of Steuben County, flows north, receives the Canisteo River from the west and the Cohocton River from the north.From the mouth of the latter, the stream takes the name Chemung River, and flows in a southeast direction, into the Susquehanna River in Pennsylvania, a few miles south of the state line.