Bernier River (Saint-François River tributary)  The Bernier River is a tributary of the Saint-François River. The "Bernier River" flows in the municipality of Stratford, in the Le Granit Regional County Municipality, in the administrative region of Estrie, in Quebec, in Canada. The river surface is generally frozen from mid-December to the end of March. Safe traffic on the ice is generally from late December to early March. The water level of the river varies with the seasons and the precipitation. The hydrographic slopes neighboring the "Bernier river" are:  The "Bernier River" has its source in a forest environment at Maskinongé Lake (Stratford). This lake is located west of "lac des îles" in Frontenac National Park (at the western limit). Triangular in shape and in length, this lake is surrounded by mountains. From Maskinongé Lake, the course of the river flows on the south shore of the Saint-François River on according to the following segments:  The Bernier river crosses a marsh with an area of 25 hectares defined as "swamp and swampy stream" which flows to the bottom of a bay on the south shore of Lake Aylmer which is crossed to the southwest by the Saint-François River. A path leads to an interpretation center and to the Maskinongé Marsh Trail. The term "Bernier" constitutes a family name of French origin. The toponym "Bernier river" was formalized on December 5, 1968 at the Commission de toponymie du Québec.