Thousand Islands

Thousand Islands, a group of more than 1,800 islands and 3,000 shoals in the St. Lawrence River, E of Lake Ontario, N N.Y. and S Ont., stretching c.50 mi (80 km) along the U.S.-Canada line. Most of the islands are in Canada; Wolfe Island, Ont. (48 sq mi/124 sq km), is the largest. The islands are part of a belt of metamorphic rock connecting the Adirondack Mts. and the Canadian Shield; they were formed at the end of the Ice Age, when the St. Lawrence River became the chief outlet of the Great Lakes. The forested region is a popular summer resort; many of the islands are privately owned, and some have castles built by former wealthy owners. There are numerous parks on the islands, including Canada's St. Lawrence Islands National Park. The five-span Thousand Islands Bridge and highway (7 mi/11 km long; opened 1938) between the New York and Ontario mainlands crosses several islands and channels.

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Thousand Islands

Group of about 1,500 small islands extending 80 mi (128 km) in the Saint Lawrence River between New York state, U.S., and Ontario, Canada. Some islands belong to Canada and some to the U.S. The Thousand Islands include summer resort facilities and the Canadian St. Lawrence Islands National Park, which was established in 1904 and covers 988 ac (400 ha). The Thousand Islands International Bridge, which contains five spans linking some of the islands and is 8.5 mi (13.7 km) long, connects New York and Ontario.