The St. Lawrence River

The St. Lawrence River extends from Quebec to Kingston on Lake Ontario. From Quebec to Montreal, the river flows calmly, permitting navigation, but between Montreal and Kingston, a succession of rapids (e.g. Lachine Rapids) render the river impracticable to navigation. To overcome these obstacles, the St. Lawrence Seaway was completed in 1959. Source: Scott, S., et al. (1989). The St. Lawrence River: Its Economy and Environment. Toronto: Centre for the Great Lakes Foundation.