Lake Champlain is a natural freshwater lake in North America along the borders of New York and Vermont and partially across the United States-Canada border in the province of Quebec . Lake Champlain ( French : lac Champlain ) is a natural , freshwater lake in North America , located mainly within the borders of the United States ( states of Vermont and New York ) but partially situated across the Canadaâ '' United States border in the Canadian province of Quebec .