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 river otters avoid water bodies with gradually sloping shorelines of sand or gravel. In Maine, use of watersheds by North American river otters is negatively associated with the proportion of mixed hardwood-softwood stands in forested areas adjacent to waterways. However, it is positively associated with the number of beaver flowages, watershed length, and average shoreline diversity. In Idaho, North American river otters prefer valley habitats over mountainous terrain, and they select valley streams over valley lakes, reservoirs, and ponds. Log jams are heavily used when present. In Florida, inhabitation of North American river otters is lowest in freshwater marshes,