Eastern Ontario - Geography

Geography

The eastern section of Eastern Ontario, that is east and southeast of Ottawa, including the towns of Cornwall, Embrun and Hawkesbury is generally a flat plain, dotted with some extensive woodlots and boggy marshes, but is primarily farmland. Certain sections here are prone to low lying flooding and spring ice jams, particularly on the banks of the South Nation River.

The Laurentian Highlands, which form a small section of the extensive Canadian Shield, cuts through the western section from the Upper Ottawa River valley southeast toward to the St. Lawrence River around Gananoque. Here sedimentary rock can be found folding over the Shield. This is also the portion where the greatest concentration of inland lakes are found. In Renfrew County, this higher terrain is called the 'Madawaska Highlands', after a major river that bisects these hills. Some highland peaks are over 400m higher than the Ottawa River. The picturesque area of the St. Lawrence River bordering New York State is known as the Thousand Islands region reflected by its numerous small islands. The bulk of the Laurentian Upland is located just to the north of the Ottawa River in adjacent Quebec and covers a vastly larger area within that province.

Along the extreme western edge of Eastern Ontario are a continuation of the Laurentian Highlands, known as the Opeongo Hills, and they contain some of the highest elevations in Southern Ontario. They stretch into the northern portions of Central Ontario, near Algonquin Provincial Park.

Ottawa itself is at the confluence of the Rideau River and Ottawa River. A series of rugged rapids and waterfalls are found along these rivers in Ottawa. Most of the underlying rock in and around the city of Ottawa is limestone bedrock, also found in abundance farther south around Kingston. Limestone was used during the construction of the Rideau Canal, which connects Kingston and Ottawa by water and was also heavily used as the building blocks for many governmental and other buildings in both cities.

The Ottawa and St. Lawrence Rivers do not actually converge in Ontario. A small portion of Quebec, Vaudreuil-Soulanges, lies between the Ontario-Quebec border and the river junction. This region has a land border with Ontario, but must cross water to reach any other part of Quebec.

The physical features of Eastern Ontario are described in the Eastern Ontario Visual Character Project.