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 throughout the year and support a living tree. Many of the islands are publicly owned. A group of 21 islands form the Thousand Islands National Park, the oldest of Canada's national parks east of the Rocky Mountains. The park hosts campgrounds, inland walking trails, annual family events, as well as a national heritage building. Thirty New York state parks are managed as part of the New York State Office of Parks, Recreation and Historic Preservation's Thousand Islands Region, including many that are located on river islands or along the New York shore. Many of these river parks were established in