Armstrong Mountain (Keene Valley, New York) Armstrong Mountain (Keene Valley, New York) Armstrong Mountain is a mountain located in Essex County, New York, named after Thomas Armstrong, a local pioneer. The mountain is part of the Great Range of the Adirondack Mountains. Armstrong Mtn. is flanked to the southwest by Gothics, and to the northeast by Upper Wolfjaw Mountain. Armstrong Mountain stands within the watershed of the East Branch of the Ausable River, which drains into Lake Champlain, thence into Canada's Richelieu River, the Saint Lawrence River, and into the Gulf of Saint Lawrence. The east side of Armstrong Mtn. drains into the East Branch of
New York (state) that includes within its borders parts of the Great Lakes and the Atlantic Ocean. The Hudson River begins near Lake Tear of the Clouds and flows south through the eastern part of the state, without draining Lakes George or Champlain. Lake George empties at its north end into Lake Champlain, whose northern end extends into Canada, where it drains into the Richelieu River and then ultimately the Saint Lawrence River. The western section of the state is drained by the Allegheny River and rivers of the Susquehanna and Delaware River systems. Niagara Falls is shared between New York and Ontario