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 often than game fishes when both are equally available. Slow-moving species include suckers (Catostomidae), catfish, sunfish and bass (Centrarchidae); and daces, carp, and shiners (Cyprinidae). For instance, Catostomidae are the primary dietary component of North American river otters in Colorado's Upper Colorado River Basin. Likewise, the common carp ("Cyprinus carpio") is a preferred fish species for the North American river otter in other regions of Colorado. Fish species frequently found in the diets of the North American river otters include: Catostomidae, which consists of suckers ("Catostomus" spp.) and redhorses ("Moxostoma" spp.); Cyprinidae, made up of carp ("Cyprinus" spp.), chubs ("Semotilus"