Lake Nipissing and the Mattawa River. Owing to the ongoing uplift of the land, the eastward flow became blocked around 4000 years ago. Thereafter Lake Nipissing drained westward, through the French River which later became a link in the historic canoe route to the West. History As it does to this day, the river played a vital role in life of the Algonquin people, who lived throughout its watershed at contact. The river is called Kichisìpi, meaning "Great River" in Anicinàbemowin, the Algonquin language. The Algonquin define themselves in terms of their position on the river, referring to themselves as the Omàmiwinini, 'down-river people'. Although a majority of the Algonquin First Nation lives in Quebec, the entire Ottawa Valley is Algonquin traditional territory. Present settlement is a result of adaptations made as a result of settler pressures. Some early European explorers, possibly considering the Ottawa River to be more significant than the Upper St. Lawrence River, applied the name River Canada to the Ottawa River and the St. Lawrence River below the confluence at Montreal. As the extent of the Great Lakes became clear and the river began to be regarded as a tributary, it was variously known as the Grand River, "Great River" or Grand River of the Algonquins before the present name was settled upon. This name change resulted from the Ottawa peoples' control of the river circa 1685. However, only one band of Ottawa, the Kinouncherpirini or Keinouch, ever inhabited the Ottawa Valley. In 1615, Samuel de Champlain and Étienne Brûlé, assisted by Algonquin guides, were the first Europeans to travel up the Ottawa River and follow the water route west along the Mattawa and French Rivers to the Great Lakes. See Canadian Canoe Routes (early). For the following two centuries, this route was used by French fur traders, voyageurs and coureurs des bois to Canada's interior. The river posed serious hazards to these travellers. The section near Deux Rivières used to have spectacular and wild rapids, namely the Rapide de la Veillée, the Trou, the Rapide des Deux Rivières, and the Rapide de la Roche Capitaine. (These rapids are now submerged under the reservoir of Holden Lake.) In 1800, explorer Daniel Harmon reported 14 crosses marking the deaths of voyageurs who had drowned in the dangerous waters along this section of the Ottawa. The main trading posts along the river were: Lachine, Fort Coulonge, Lac des