The Grand River Bostonnais flows in the municipality of Rivière-à-Pierre, in Portneuf Regional County Municipality, in the administrative region of Capitale-Nationale, in Quebec, in Canada.

From "lake Vesses-de-Loup", at an elevation of about 360 metres (1,180 ft) above sea level, which is the main head of the river, water goes down through nine lakes including: Lepiota, "de la Grande Recoupe" (Great Trimming), Dubord and "lac du Barrage" (Lake of the dam).

A river segment is 1.4 kilometres (0.87 mi), between the "lac de la Grande Recoupe" and lake Dubord; 1.4 kilometres (0.87 mi) between "Lac du barrage" and the Batiscan River.

The second head of the "Grand River Bostonnais" (Portneuf) is lake Guilbeault; it flows a further 2.5 kilometres (1.6 mi) before emptying into the Grand River Bostonnais.

[1] The name "Bostonnais" means in French "people living in Boston" in the U.S. state of Massachusetts.