The Ottawa River
Ottawa River, or, a river in southwestern Quebec and southeastern Ontario. It is about 790 miles (1,270 km) long and is a principal tributary of the St. Lawrence River. From its source in the Laurentian Mountains of Quebec, the Ottawa flows generally westward and then southeastward, forming Lake Timiskaming (Lac Témiscamingue) and part of the Quebec-Ontario border. The river empties into the St. Lawrence a short distance downstream from Montreal.
The Ottawa is navigable for light shipping in its lower course and is connected with Lake Ontario by the Rideau River and Canal Tributaries include the Madawaska, Coulonge, Gatineau, and Lièvre rivers. Gatineau, Quebec, and Ottawa, Ontario, are leading cities on the Ottawa River. The river is used for lumbering operations.