The main neighboring
watersheds of the Blanche river are: • to the north: Old Mill Creek,
Osgood River,
Sunday River,
Perry River; • to the east:
Bécancour River,
rivière de l'Or,
Prévost-Gilbert River; • in the south: Bécancour River,
Coleraine River; • to the west: Bécancour River,
Bagot River. The Blanche River draws its source from a mountain stream located on the east side of
Mont Saint-Adrien and west of downtown
Thetford Mines. The Blanche river flows on towards the south, mainly in forest territory, according to the following segments: • south to the road; • southward, up to
route 122 which it cuts to the southwest of the city of Thetford Mines; • towards the south, until its mouth. The Blanche River empties on the north shore of the
Bécancour River, northeast of Black Lake, near an open pit mine. == Toponymy ==