Ausable River, NY

The Ausable River, 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 town of Lake Placid and Au Sable Forks to empty into Lake Champlain (at 44°33′40″N 73°25′25″W / 44.56111°N 73.42361°W / 44.56111; -73.42361Coordinates: 44°33′40″N 73°25′25″W / 44.56111°N 73.42361°W / 44.56111; -73.42361) a few miles east of Keeseville, New York. The river forms a partial boundary between Clinton County and Essex County. The Ausable River is known for its spectacular gorge, Ausable Chasm, and its trout fishing.

The upper portion of the river is separated into an East and a West Branch, which converge in Au Sable Forks. The West Branch of the Ausable arises from the conjunction of the MacIntyre, South Meadow and Marcy Brooks, east of Mount Jo near the Adirondak Loj; it then runs 36 miles (58 km) northeast to Au Sable Forks (44°26′25″N 73°40′28″W / 44.44028°N 73.67444°W / 44.44028; -73.67444), and is fed by Lake Placid and the Chubb River along the way. At high water-levels, the upper end provides demanding white-water paddling opportunities. Further along, it runs through the Wilmington Notch, a gorge formed by a fault zone, with 700-foot (210 m) cliffs on one side and 1,700-foot (520 m) cliffs on the other.

The East Branch arises from Upper and Lower Ausable Lakes in the Ausable Valley, which forms the south side of the Great Range. The first four miles are especially scenic, and can be viewed from trails on either side maintained by the Adirondack Trail Improvement Society. The river is then met by the Cascade Brook which flows from the Cascade Lakes, beneath Cascade Mountain, on its way to Au Sable Forks.

The AuSable River river is 94 miles long and drains a 516 square mile watershed.