The Rivière des Prairies, called the Back River in English, is a delta channel of the Ottawa River in southwestern Quebec, Canada. The Kanien'kehá:ka called it Skowanoti, meaning "River behind the island". The river separates the cities of Laval and Montreal.

The Ottawa River is a river in the Canadian provinces of Ontario and Quebec. It is named after the Algonquin word 'to trade', as it was the major trade route of Eastern Canada at the time. For most of its length, it defines the border between these two provinces. It is a major tributary of the St. Lawrence River and the longest river in Quebec.