The Thousand Islands are a chain of islands that straddle the U.S.-Canada border in the Saint Lawrence River as it emerges from the northeast corner of Lake Ontario. The islands stretch for about 50 mi (80 km) downstream from Kingston, Ontario. The Canadian islands are in the province of Ontario. The U.S. islands are in the State of New York. The islands, which number 1,865 in all, range in size from over 100 km² to smaller islands occupied by a single residence, to even smaller uninhabited outcroppings of rocks that are home to migratory waterfowl. The number of islands was determined using the criteria that any island must be above water level for 365 days per year and support at least one tree or shrub. Geologically, the islands are located where a branch of the Canadian Shield runs south across the river to join with the Adirondacks.

---