Lake Champlain, the sixth-largest body of fresh water in the United States, separates Vermont from New York in the northwest portion of the state. From north to south, Vermont is long. Its greatest width, from east to west, is at the Canada–U.S. border; the narrowest width is near the Massachusetts border. The width averages . The state's geographic center is approximately three miles (5 km) east of Roxbury, in Washington County. There are fifteen U.S. federal border crossings between Vermont and Canada.