The surface of Lac Métascouac is usually frozen from the beginning of December to the end of March, however the safe circulation on the ice is generally made from mid-December to mid-March.

Surveyor Frederic William Blaiklock explored in 1847 the territory between Stoneham, near Quebec (city), and Métabetchouan–Lac-à-la-Croix, at Lac-Saint-Jean, with a view to the possible construction of a road connecting these two points.

Surveyor Henry O'Sullivan explored the site in 1892 and described the lake as one of the most beautiful in the entire Métabetchouane river basin, dotted with green islands and bordered on each side by gently sloping hills.

The first makes “Métascouac” come from the Innu words “matau” and “iskwewak” which we translate by “lac aux belles femmes”, however, casting some doubt as to this interpretation.

However, when he published his "Dictionnaire montagnais-français" in 1901, Father Lemoine himself gave the toponym the meaning of "place where three streams meet".