The Ausable River /ɔːˈseɪbəl/, also known as AuSable River and originally written as "Au Sable", runs in the U.S. state of New York, from the Adirondack Mountains and past the village of Lake Placid and Au Sable Forks to empty into Lake Champlain (at (44°33′40″N73°25′25″W) It has an East and West branch that join at Ausable Forks NY. A few miles east of Keeseville, New York. The river forms a partial boundary between Clinton County and Essex County.