The Rivière à Mars is a tributary of the Baie des Ha! Ha! Crossing the borough La Baie, in Saguenay (city), in the administrative region of Saguenay–Lac-Saint-Jean, in Quebec, in Canada. The "rivière à Mars" is a tributary of the Saguenay River and has its source in the Laurentides Wildlife Reserve. This river to salmons was badly affected by the Saguenay Flood which occurred from July 19 to 21, 1996.

The Baie des Ha! Ha! is a particularly developed cove over a length of eleven kilometres on the Saguenay River in the region of Saguenay–Lac-Saint-Jean in Quebec, Canada. At the end of this natural corridor, which was originally called in French the "Grande Anse", then the "Grande Baie", there are the Ha! Ha! River and Rivière à Mars. According to the Second Saguenay theory, this vast depression is the extension of the fault and collapse ditch of the Kenogami Lake which is located upstream less than twenty kilometers.