The Laval River originates in Lac Septembre and flows generally southeast through Lac Roger, Lac Kinney, Lac Stanley and Lac Laval, which it enters at the southwest angle and leaves from the southeast end. The Lac Laval, from its mouth, is sometimes taken as the source of the river. The river then flows through Lac Éric and Lac Courdeau, then enters a flat-bottomed valley where it is fed by the Adam River, receives water from Lac MacDonald and Lac Madeleine, and then enters Lac à Jacques. Below this lake, after some rapid sections, the river passes under Quebec Route 138 at Pont-Laval, near its mouth. The Laval River Rare Forest is on the east side of the river between Lac à Jacques and Route 138. It is unusual in including red pines, which are very rare on the Côte-Nord. The river enters the Saint Lawrence in the Baie Laval just north of the community of Forestville. The Pointe Laval defines the southeast point of the bay, and the Île Laval is in the mouth of the bay. The rate of flow of the river varies considerably, from slow to fast. The bed of the river is rather dark, the waters are not very clear, and some of the pools are black. After rain the river level and color change significantly.
Fishing
For many years Anglo Pulp and Paper, a paper mill, owned the fishing rights, until the government of Quebec made the river a wildlife reserve. The Forestville Hunting and Fishing Association was formed on 16 October 1968, and in 1978 became responsible for a reserve known as the Forestville ZEC. The Association took over management of the Laval River in spring of 1980. The Forestville Hunting and Fishing Association now manages the River Laval ZEC. There are 67 salmon pools and 45 trout pools. Both the Atlantic salmon and the sea trout are plentiful and are much larger than average. The large Lac à Jacques holds excellent northern pike. In May 2015 the Ministry of Forests, Wildlife and Parks of Quebec announced a sport fishing catch-and-release program for large salmon on sixteen of Quebec's 118 salmon rivers. These were the Mitis, Laval, Pigou, Bouleau, Aux Rochers, Jupitagon, Magpie, Saint-Jean, Corneille, Piashti, Watshishou, Little Watshishou, Nabisipi, Aguanish and Natashquan rivers. The Quebec Atlantic Salmon Federation said that the measures did not go nearly far enough in protecting salmon for future generations. In view of the rapidly declining Atlantic salmon population catch-and-release should have been implemented on all rivers apart from northern Quebec. In 2019 the Upper North Shore Watershed Agency conducted inventories of the fish in the Laval River's tributaries. They had studied the spawning grounds of the river in 2018, and concluded there was no obstacle to the salmon run on one of the tributaries. Three more tributaries had been identified that could be accessible. By better understanding the streams used for reproduction by the Atlantic salmon they would be able to better protect the environment and thus protect the fish.
