Thousand Islands level year-round, and support at least two living trees. The Thousand Islands archipelago is located at the outlet of Lake Ontario at the head of the Saint Lawrence River. The region is bisected by the Canada–United States border and covers portions of Jefferson and St. Lawrence counties in the U.S. state of New York, in addition to parts of the United Counties of Leeds and Grenville and Frontenac County in the Canadian province of Ontario. Geologically, most of the islands are located where a branch of the Canadian Shield runs south across the river to join with the Adirondacks. The
Thousand Islands in the mid-1990s with the arrival of zebra mussels, which feed on algae. The water is so clear in some areas that a rocky bottom can be observed in of water. The area has several shipwrecks, and although most of them are over underwater, some are a mere down and can be seen from the surface. Prior to European colonization, the Thousand Islands region was home to, or visited by, members of the Iroquois Confederacy and Ojibwa people. Their name for the islands was "Manitouana" or the "Garden of the Great Spirit". The region was a part of the War