Get to know the Chemung River Friends The Chemung River flows 45 miles through three counties and the state of New York and Pennsylvania. Most of it winds through Chemung County. The Friends of the Chemung River Watershed (River Friends) is a nonprofit organization working to protect and promote the river and its major tributaries – the Canisteo, Cohocton and Tioga rivers. The water from those waterways flows more than 300 miles to the Chesapeake Bay in Maryland. River Friends, headquartered in Elmira, helps build and maintain boat launches and river trails. We lead guided eco-recreation ...