The river exits the lake at Outlet Bay, passes under Ontario Highway 560 and continues northeast.

It reaches The Forks at Matachewan and takes in the major left tributary West Montreal River.

It continues northeast briefly to Fox Rapids, then turns southeast, passes under Ontario Highway 65, takes in the right tributary Sydney Creek and left tributary Council Creek and reaches the Ontario Power Generation (OPG) Indian Chute Generating Station and dam at Indian Chute Falls.

Aubrey Cosens VC Memorial Bridge carrying Ontario Highway 11, attains OPG Hound Chute Generating Station and dam and further downstream Canadian Hydro Developers' Ragged Chute Generating Station and dam.

The river flows over Fountain Falls and the Paugan Rapids, and enters the reservoir of the OPG Lower Notch Generating Station and dam.