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
Thirty Thousand Islands kilometres west of Beausoleil Island are four more islands – Giants Tomb Island, Hope Island, Beckwith Island, and Christian Island. To the west of French River Provincial Park are many more islands, including Manitoulin Island, the largest freshwater lake island in the world. Many of the Group of Seven landscape paintings feature the Georgian Bay Shoreline and the adjacent windswept islands with their distinctive trees and large boulders, which are characteristic features of the Canadian Shield. Franklin Carmichael, A.Y. Jackson, Arthur Lismer, Frederick Varley, A.J. Casson and Tom Thomson all painted extensively along Georgian Bay. At that time, they came