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
Thousand Islands Railway build the line; that company already operated steamship docks in the village. The original line opened 1 January 1884. The company name was changed to Thousand Islands Railway four months later. A swing bridge over the mouth of the Gananoque River was constructed in 1894 to provide service to businesses on the east side of the river. The line originally served to carry timber and freight to Gananoque's docks, where it could be loaded onto ships. While available timber stocks soon diminished, passenger traffic increased as the Grand Trunk under Charles Melville Hays promoted the tiny town as a vacation