The river is generally frozen from November to April; however, the period of safe circulation on the ice is usually from mid-December to the end of March.

The "Somme river" originates from Lac Noir (about 166 m in diameter; altitude: 479 m) in the municipality of Saint-Gabriel-de-Valcartier.

The river continues south for 1.9 km in Shannon crossing a marshy area, until the outlet of the lakes: "à la voile", "étang long", Try, "on the Island" and Ravenna.

[1] This Quebec toponym originates from the river Somme which flows in the North-West of France in region Hauts-de-France.

The Quebec toponym "rivière de la Somme" is linked to the Quebec toponym Mont Sorrel which evokes a mountain near Ypres, in Belgium, where is occurred in the salient of Ypres a battle of the First World War between three divisions of the 2e British Army and three divisions of the IVth German Army, from June 2 to June 14, 1916.