The glaciation receded approximately 10,000 years ago. 


The departure of the glacier ice resulted in the formation of more than 150 lakes of varying sizes and characteristics. Small lakes in bogs, with dark acid water, are generally situated in higher altitudes, and the large, deep clearwater lakes follow the valley bottoms. 

They are all interconnected by a network of brooks or small cascading rivers that ultimately flow into the Matawin and Saint-Maurice rivers.

Among the treasures of the park are four large lakes in the Lac du Caribou sector that contain only Brook Trout. Français Lake supports the only Arctic Char population.

The park waters are principally acidic or neutral. They support a low biological productivity characteristic of young lakes also called oligotrophic. The natural acidity is accentuated by acid rains. This phenomenon is particularly important and probably has more effect on the smaller head lakes than on large water bodies.

Beginning in 1849, the presence of forest exploitation is noted on the territory. For 120 years, logging and log driving were in activity on the majority of the park waters. Traces of this era are visible everywhere: old dams, logging roads, accumulations of logs on lake bottoms, eroded sediments, dragged streams to permit the passage of logs and stone piles to orient the flow of water.
Man has profoundly modified the aquatic environment. The recent disappearance of 38 populations of Brook Trout are proof of this. Keeping this in mind, we are attempting to understand the state of our resources and develop conservation strategies required for the protection and maintenance of the natural characteristics of this territory. Learn more about our lakes conservation and restoration project.