The St. Lawrence Seaway is a deep waterway extending 3,700 km (2,340 miles) from the Atlantic Ocean to the head of the Great Lakes, at the heart of North America. Within the meaning of the legislation which provided for the construction and maintenance of the deep waterway, the St. Lawrence Seaway proper extends from Montreal to Lake Erie.
The Montreal/Lake Ontario section encompasses a series of 7 locks from Montreal (Quebec) to Iroquois (Ontario) enabling ships to navigate between the lower St. Lawrence River and Lake Ontario.
The opening of the Seaway, in April of 1959, marked the full realization of a 400 year-old dream. In the early part of the 16thcentury, Jacques Cartier, the French explorer, was turned back by the rushing waters of the Lachine Rapids, just west of what is now Montreal, and thus denied
his dream of finding the Northwest Passage and the route to the East. At various times during the intervening 300 years, canals have been dug and locks built around the natural barriers to navigation in the St. Lawrence River.
This activity was spurred on by the desire to make use of the economical transport route which the waters of the Great Lakes Basin offered for the movement of goods in and out of this area of the continent.