The Saskatchewan River is 1,939 km long from the Rocky Mountains headwaters to Cedar Lake in central Manitoba. When including its longest tributary, the South Saskatchewan River, the Saskatchewan River is the fourth-longest river in Canada. It’s a major tributary to the Nelson River, ultimately draining into Hudson Bay. Its name is derived from the Cree word kisiskâciwanisîpiy meaning swift-flowing river. The Saskatchewan River was a major transportation route for First Nations for thousands of years and was an instrumental transportation and resource corridor during the fur trade and early European exploration.