The Rivière Cachée (English: Hidden River) is a tributary of the Saint-Maurice River,[1] flowing on the north bank of the Saint Lawrence River, entirely in Notre-Dame-du-Mont-Carmel (Parish Municipality), in Les Chenaux Regional County Municipality (RCM), in Mauricie administrative region, in province of Quebec, Canada.

The course of the Hidden River descends mainly in the forest zone, passing on the west side of the Notre-Dame-du-Mont-Carmel (Parish Municipality.

The Hidden River rises at the mouth of Valmont Lake (length: 0.7 kilometres (0.43 mi); altitude: 122 metres (400 ft)).

This lake is located in the southern part of a large swamp area which extends in the sector of Shawinigan-Sud, in Lac-à-la-Tortue and Saint-Narcisse.

The confluence of the Cachée river is located upstream of the La Gabelle dam at: The sinuousness of its course at the bottom of a flow in the lower part explains the hidden character of the river.