| Lake Saint Francis | |
|---|---|
| lac Saint-François | |
 View of Lake St. Francis fromHighway 2 inSouth Glengarry, Ontario, near the Quebec border. | |
  Lake Saint Francis | |
| Location | Ontario/Quebec/New York |
| Coordinates | 45°10′N74°22′W / 45.167°N 74.367°W /45.167; -74.367 |
| Type | lake |
| Primary inflows | Saint Lawrence River |
| Primary outflows | Saint Lawrence River |
| Basin countries | Canada, United States |
| Settlements | Salaberry-de-Valleyfield |
| Official name | Lac Saint-François |
| Designated | 27 May 1987 |
| Reference no. | 361[1] |
Lake Saint Francis (French:lac Saint-François,pronounced[laksɛ̃fʁɑ̃swa]) is alake which borders southeasternOntario, southwesternQuebec and northernNew York State. It is located on theSaint Lawrence River betweenLake Ontario andMontreal, Quebec. The lake forms part of theSaint Lawrence Seaway.
The city ofSalaberry-de-Valleyfield is located at the east end of the lake.
Lac Saint-François National Wildlife Area, located on the south shore of the lake, protects wetlands located on the shores of the lake. This area provides important habitat forRedhead ducks and other waterfowl. Thousands of migrating waterfowl stop over in this region. In 1987, it was recognized as awetland of international significance under theRamsar Convention.
The Charlottenburgh Marsh, including Cooper Marsh, is an important wetland area located on the north shore of the lake.