The discovery of artifacts dating to a period extending from 6 000 to 4 000 years ago recalls the presence of Aboriginal peoples on this site.
With a history spanning 7,000 years, the site was a portage and encampment location used by Amerindians to avoid the rapids, a military fortification, and a canal that opened the way for commercial shipping. The site at Coteau-du-Lac represented a major point of transit for British military logistics efforts. Between 1781 and 1814, the army developed large-scale infrastructures on the site, which testify to the importance the colonial authorities attached to improving and protecting transportation and communications along the route linking Montréal and Kingston.
The "Coteau rapids" are located between Lake St. François and Lake St. Louis, and are the narrowest and most turbulent section of the entire St. Lawrence River. In the less than 13 km separating the Great Lakes from the St. Lawrence Valley proper, the River hurtles over three sills for a total drop of 25.6 m.