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St. Marys River



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Each Heritage River Story Map displays various visual representations of geospatial data in combination with text, photos, videos and external links.

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Natural Heritage

The St. Marys River flows 125 km from Lake Superior’s Whitefish Bay through Sault Ste. Marie, dividing into two channels around St. Joseph Island before emptying into Lake Huron.

The river has three distinct hydrological reaches: the 22.5 km upper reach, from the narrow outflow of Lake Superior to Sault Ste. Marie, which is characterized by strong winds, clear cold water, and a generally shallow, sandy coastline with offshore sand and gravel shoals; the 2.5 km rapids reach at Sault Ste. Marie where 6.1 metres of the river’s 6.7 metre drop occurs through a long, shallow fall over boulders and sandstone outcrops, past Whitefish Island, the Sault Canals and power dams; and the 100 km lower reach to Bruce Mines and Detour, along which broad shallow lakes and rock-fringed channels alternate.

Flowing through 2.5 billion year-old Precambrian rock sculpted by glaciers, the river stands at the geological crossroads of the continent, as well as at the hydrological and ecological junction of the Upper Great Lakes. Its valley provides dynamic evidence of the major processes that shaped the northern half of the North American continent.

The river valley lies within the Great Lakes St. Lawrence Mixed Forest Region typified by coniferous black and white spruce, balsam fir, red and white pine and hardwoods such as birch, poplar and maple. Species such as beech, ash, basswood and horse chestnut grow here, close to their northern limits. Rare plants occur at Gros Cap, Mark’s Bay and Whitefish Island, and there are significant wetlands at Gros Cap, Mark’s Bay, Echo Bay and Hay Point. Shorebirds, raptors and waterfowl are all plentiful.

Cultural Heritage

The St. Marys River packs a lot of history into its short reach. As early as 2,500 BCE the Ojibwe people had established settlements on islands and along the shore of the river to harvest the abundant whitefish. The Métis people of Canada originated in the valley, and the Batchewana and Garden River First Nations still live along the river’s shores.

After its exploration in 1621 by Étienne Brule, the St. Marys became a key part of the fur trade route. Fort St. Joseph was built in 1796 in part for traffic control on this busy route, as well as for its crucial strategic location, which ensured the area remained under British control during the War of 1812.

The first commercial lock around the rapids was built on the American side of the river in 1855, but the Chicora incident of 1870, in which right of passage through the lock was denied to the Chicora on the grounds that it was a military vessel, heightened the demand for an all-Canadian route. In 1895, the Canadian Sault Ship Canal – at the time the most advanced in the world -was completed. The application of electricity generated on-site to operate the gates and fill and drain the lock, and the novel Emergency Swing Bridge Dam marked it as unique.

For many years, the combined American and Canadian ‘Soo Locks’ were the busiest such systems in the world. In 1985, the operation of the Sault Ste. Marie Canal was transferred to Parks Canada whose responsibility it is to preserve and interpret the Canal’s natural and cultural resources. Following the failure of the lock wall in 1987, a recreational lock was built into the original structure, and the Canal reopened to great fanfare on July 14, 1998.

Between 1899 and 1903 the Lake Superior Corporation was established beside the St. Marys Rapids, where Ontario’s first steel was poured. The descendants of this empire still dominate the industry of the river valley in the form of Algoma Steel Inc., the St. Mary’s Paper Company, and the Great Lakes Power Corporation.

The establishment of the Ontario Provincial Air Service at Sault Ste. Marie in 1924 and the construction of its waterfront hangars, marked a new era in the aerial supervision of Ontario’s forest resources and in the use of float planes in fighting fires from the air. The Canadian Bushplane Heritage Centre is a tribute to this important aspect of Canada’s forest history.

Recreational Heritage

The St. Marys River can be enjoyed in countless ways from land and from the water.

The Voyageur Trail, hiking trails, boardwalks and waterfront parks offer great opportunities to experience the waterway on foot. Sailing, motor and pleasure boats, canoes, kayaks and tugboats are all available to ply the waters – or you can remain on shore as a spectator. Fishing is also popular both in summer and on the ice; species include whitefish, perch, walleye, lake trout, pike, bass, salmon and rainbow trout.

Beaches provide access to the water for swimming, waterskiing, windsurfing and scuba diving in warmer months. In the winter, skating, snowmobiling, and cross-country skiing are popular.

Fun Fact

Whitefish Island, once one of the largest aboriginal settlements in the upper Great Lakes, was inhabited from 200 BCE to 1895.

River Managers

The Sault Ste. Marie Region Conservation Authority is responsible for the management of this Canadian Heritage River. The locks and canal are a national historic site and are managed by Parks Canada.

Discover More


The outstanding cultural values and recreational heritage of the St. Marys River led to its designation to the Canadian Heritage Rivers System in 2000.

The 125 km river, which flows eastward out of Lake Superior into Lake Huron, has long been a strategic link for travel across the continent. Lock and canal building began as early as 1798, when the Northwest Company built small locks for fur trade canoes to pass around the rapids. The Canadian lock, completed in 1895, was the most advanced in the world at that time. Now a national historic site managed by Parks Canada, it was rebuilt and opened to pleasure craft in 1998.


title type file
St. Marys River Monitoring Report 2000 - 2011 Archived / archive en anglais seulement Decadal Monitoring Reports PDF of St. Marys River Monitoring Report 2000 - 2011

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Plaque Text

The Canadian Heritage River plaques offer a brief glimpse into why a river has been designated to the System. They are often located nearby one of its historically significant locations, and highlight some of the most important natural, cultural and recreational values of the river. 

St. Marys River Plaque Text

The St. Marys River - Connecting three of North America’s Great Lakes – Superior, Huron and Michigan – the St. Marys River is the key hydrological, ecological and transportation link in the Great Lakes system. Since its birth less than 10,000 years ago at the end of the most recent Ice Age, this historic river, although only 125 km long, has been a vital artery leading to the heart of the continent and beyond.

The St. Marys River valley is the cultural heartland of the Ojibwe, and for almost 5,000 years Aboriginal peoples have gathered here to fish and trade. For explorers, missionaries and fur traders, the St. Marys was the gateway to the west. In the late 18th century, the British military recognized the value of the river’s strategic location for the defence of Canada, and built Fort St. Joseph. In the 19th century, locks circumventing the rapids connected the commerce and industry of eastern North America to the untapped natural resources to the west. Although still a significant route of commerce, the St. Marys River is now an important playground for sport fishers and boaters.

The designation of the St. Marys River as a Canadian Heritage River is a testament to the commitment of local residents who share a vision for the recognition and preservation of this river’s outstanding natural, cultural and recreational values.