The Bécancour takes its source from the lake of the same name in the town of Thetford Mines, in the Chaudière-Appalaches region.

[1] The course of the Bécancour, which is 196 kilometres (122 mi), begins at 402 metres (1,319 ft) of altitude in the Appalachian Mountains.

It follows a winding route to Lyster, which marks its entry into the St. Lawrence Lowlands.

[3] The city of Thetford Mines diverts part of the waters of the Saint-François basin for the benefit of Bécancour via its aqueduct, that is 19,000 cubic metres per day (7,800 cu ft/ks).

[8] Bécancour is part of two geological provinces, namely the Appalachians upstream and the St. Lawrence Lowlands downstream.

[9] The Appalachians are composed of sedimentary rocks and volcanic which have been deposited in a deep marine environment.

[10] In the plain downstream of the basin, the main forest species are gray birch, trembling aspen, white spruce and balsam fir.

[10] The top of the mountains near Thetford Mines are favorable to white birch while at the bottom of the slopes we find balsam fir and tamarack.

[14] The toponym Rivière Bécancour was formalized on December 5, 1968, at the Commission de toponymie du Québec.

[7] The “Piste Bécancour” (Abenaki Becancour Trail), linked the Grand lac Saint François, via the Petit lac Saint-François (Ashberham), in the canton of Coleraine, to the basin of the Bécancour River to Wôlinak.

[16] A village named "Wananoak" located near the sources of the river and a path leading to Lac Mégantic is inscribed on a Mitchell Map of 1755.