| Lake of Two Mountains | |
|---|---|
| Île aux Tourtes Bridge across Lake of Two Mountains | |
| Location | Deux-Montagnes Regional County Municipality / Vaudreuil-Soulanges Regional County Municipality / Montréal, Quebec |
| Primary inflows | Ottawa River |
| Primary outflows | Rivière des Mille Îles, Rivière des Prairies |
| Basin countries | Canada |
Lake of Two Mountains (French: lac des Deux Montagnes) is part of the river delta widening of the Ottawa River in Quebec, Canada, where it feeds into the St. Lawrence River.
Lake of Two Mountains has four outflows: Rivière des Mille Îles and Rivière des Prairies, bordering Île Jésus, and two branches of the Ottawa River, flowing into the St. Lawrence via Lake Saint-Louis, on either side of Île Perrot.
The city of Deux-Montagnes is located on the lake's north shore, where it flows into Rivière des Mille Îles. The southwest portion of the city of Montréal borders the eastern part of the lake, as does the now de-merged village of Senneville.
The lake was first named lac des Médicis in 1612 by Samuel de Champlain, then renamed lac des Soissons about 1632, and ended up bearing its current name around 1684. The name refers to the two highest peaks of Mont Oka, near Oka, that face the lake on its northern shore, Calvaire Mountain and Saint-Joseph-du-Lac Hill.