The Wessonneau River flows north-east in the Mekinac Regional County Municipality in Mauricie, in Quebec, in Canada, on the west bank of the Saint-Maurice River.

Its mouth is located at the opposite of the hamlet "Rivière-aux-Rats", which is on the east side of Saint-Maurice River, at 29.5 km ( by Route 155) south of Downtown La Tuque.

[1] The altitude of the water at the confluence is 121 m. In its watershed, highest mountainous peak reaches up to 381 m. The mouth of the Wessonneau North River empties into the river Wessonneau about 10.2 km from the mouth of the latter.

From the bridge of the "Rivière aux rats", a fork in the road heads west along the route of the river Wessonneau by the north shore.

From the bridge, on three kilometers high mountains are bordering the north side of the road.