Besides the village areas, forestry is the main economic activity in this valley; agriculture, second especially in the lower part.

[1] The surface of the Salmon River is usually frozen from mid-December to mid-March, except the rapids areas; however, safe circulation on the ice is generally from late December to early March.

The main hydrographic slopes neighboring the Salmon River are: The Rivière au Saumon constitutes the outfall of lake Brompton, the mouth of which is located northeast of the lake, north of the hamlet "Lac-Brompton", in the territory of the municipality of Saint-Denis-de-Brompton.

From the route 222 bridge located at the mouth of Lac Brompton, the Salmon River flows to the bottom of a valley on: The Rivière au Saumon flows on the west bank of the Saint-François River at 0.9 km (0.56 mi) downstream from Morin Island, at 10.2 km (6.3 mi) downstream Pont des Papetiers (connecting the hamlet of "Greenlay" and the town of Windsor) and 3.8 km (2.4 mi) upstream of the Mackenzie Bridge (connecting Melbourne and Richmond).

The toponym "Rivière au Saumon" was officially registered on December 5, 1968, at the Commission de toponymie du Québec.