It is the francophone centre of the otherwise largely (57%) anglophone Pontiac MRC, with 79.6% listing French as their mother tongue in the Canada 2006 Census.

In the late 17th century the site was occupied, perhaps intermittently, by members of the d'Ailleboust family, who used "sieur de Coulonge" as a title.

Accounts differ: the Commission de toponymie du Québec mentions Nicholas d'Ailleboust de Manthet, who wintered in that location in 1694;[1] Elizabeth Browne Losey says it was founded by the d'Ailleboust family 'as early as 1650'.

[4][5] The trading post became the village of Fort-Coulonge situated several kilometres down river, when in 1843, the region's first sawmill was built by George Bryson Sr.

The many logging camps in the Ottawa Valley created a big demand for accommodation in the town; by the 1890s there were at least 5 hotels.

The town's mills produced thousands of feet of cut lumber, as well as pulp wood.