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
North American river otter American riverotters are characteristically small or are a type species found in riparian zones. The few occurrences of mammals found in the North American river otter's diet include: muskrats ("Ondatra zibethicus"); meadow voles ("Microtus pennsylvanicus"); eastern cottontails ("Sylvilagus floridanus"); and snowshoe hares ("Lepus americanus"). Records of North American otters preying upon North American beavers ("Castor canadensis") vary; it has been reported in the southern boreal forest of Manitoba. Trappers in Alberta, Canada commonly assert North American river otters are major predators of North American beavers. A 1994 river otter study reported findings of beaver remains in 27 of 1,191 scats