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
Islands in the River Thames or more artificial lock islands separating the lock from the weirs. These may have been created by building an artificial island in the river or by digging an artificial canal to contain the lock and turning the land between that and the river into an island. In many cases the lock island contains the lock keeper's house and can be accessed across the lock gates. Such lock islands are only listed above if they have a specific name of their own: all Thames locks are listed in Locks on the River Thames. Islands in the River Thames This article lists