 After a course of a few miles in Pennsylvania, it again enters New York and flows in a general westerly direction to near the western border of Tioga County, whence it turns south and again enters Pennsylvania.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.