Black Mountain (Washington County, New York) Black Mountain (Washington County, New York) Black Mountain is a mountain located in Washington County, New York, of which its peak is the highest point. Isolated from the rest of the Adirondack Mountains by Lake George, Black Mtn. has the seventh highest topographic prominence of all the mountains in New York. Black Mountain stands within the watershed of Lake Champlain, thence into Canada's Richelieu River, the Saint Lawrence River, and into the Gulf of Saint Lawrence. The northwest and south sides of Black Mtn. drain into Lake George, thence into La Chute River, and Lake Champlain. The northeast side of
New York (state) New York and Ontario sharing the Thousand Islands archipelago within the Saint Lawrence River, while most of its border with Quebec is on land; it shares Lake Champlain with the New England state of Vermont; the New England state of Massachusetts has mostly a land border; New York extends into Long Island Sound and the Atlantic Ocean, sharing a water border with Rhode Island, while Connecticut has land and sea borders. Except for areas near the New York Harbor, New York has a mostly land border with two Mid-Atlantic states, New Jersey and Pennsylvania. New York is the only state