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.