The main hydrographic slopes near the "Port aux Quilles River" are: • North side:
Rivière de la Baie des Rochers,
Saguenay River; • East side: Anse à Poitras,
St. Lawrence River; • South side:
Noire River,
Port au Persil River,
Port au Saumon River,
Rivière à la Loutre (La Malbaie),
Malbaie River; • West side:
Noire River. The Port aux Quilles River rises at the mouth of Port aux Quilles Lake (altitude: ) in the forest zone, at the foot of the Montagne de la Croix. On the outskirts of this lake, the resort is established around the eastern bay, near the mouth, because of the path of Port aux Quilles Lake which serves this area. From the mouth of Port aux Quilles Lake, the course of the Port aux Quilles River descends by traveling according to the following segments: • southeasterly, crossing the Mare Lake to the outlet (coming from the north) of the Trout Lake; • easterly collecting the dump (coming from the north) of Lakes Henri, Rouge et Bleu, to a bend in the river corresponding to the dump (coming from the north) of the Falaise lakes and Mosquito; • south-easterly to the outlet (coming from the south) of Lac Épiphane, then east, forming several small streamers to the outlet of Lac Ceci (coming from South); • northerly, forming a hook to the west, to the outlet of Lake Arthur-Savard (coming from the east); • to the east, forming two successive curves towards the south, notably passing under Hydro-Québec's high-voltage lines, winding up to the confluence of a stream draining Lake Ennis (coming from the north). Note: This confluence is located just southwest of the center of the hamlet Port-aux-Quilles; • southeasterly by cutting
route 138 and collecting the Harvey Lake (from the southwest) discharge to the dump (coming from the northeast) of Seeds Lake; • to the southeast crossing a series of rapids and waterfalls between two mountains, and collecting a stream (from the southwest) to the bottom of the "Anse de Port aux Quilles", which is open on the
Gulf of St. Lawrence. ==Toponymy==