The Don Valley

The Don River is a watercourse in southern Ontario that empties into Lake Ontario, at Toronto Harbour. Its mouth was just east of the street grid of the town of York, Upper Canada, the municipality that evolved into Toronto, Ontario. The Don is one of the major watercourses draining Toronto that have headwaters in the Oak Ridges Moraine.

The Don is formed from two rivers, the East and West Branches, that meet about 7 kilometres north of Lake Ontario while flowing southward into the lake. The area below the confluence is known as the "lower Don", and the areas above as the "upper Don". The Don is also joined at the confluence by a third major branch, Taylor-Massey Creek. The Toronto and Region Conservation Authority is responsible for managing the river and its surrounding watershed.