Thousand Islands – Frontenac Arch is one of four ecoregions of the Mixedwood Plains. The Thousand Islands in the Saint Lawrence River have a distinctive flora and fauna and are a part of the biological corridor. The bedrock is mostly gneiss, granite and marble, more than a billion years old. The Frontenac terrain is the youngest of the Ontario portions of the arch, dated at 1.2 billion years old. These rocks were once part of a large mountain chain of the ancient supercontinent of Rodinia. There is also a meteor crater near Holleford, where the shield meets the limestone plains of southeastern Ontario. The area
North American river otter Instances of North American river otters eating small mammals, such as mice and squirrels, and occasionally birds have been reported as well. There have also been some reports of river otters attacking and even drowning dogs. The range of the North American river otter has been significantly reduced by habitat loss, beginning with the European colonization of North America. In some regions, though, their population is controlled to allow the trapping and harvesting of otters for their pelts. North American river otters are very susceptible to the effects of environmental pollution, which is a likely factor in the continued decline