This ecoregion includes much of the rugged Laurentian Highlands of southwestern Quebec. It also includes the Gouin Reservoir area and extends northward from near Quebec City to near Lac Saint-Jean along the north shore of the St. Lawrence River. From Lac Saint-Jean, it extends to the Cabonga Reservoir in the Laurentian Highlands. In the south, it extends westward from Quebec City to the Ottawa River valley. It is marked by warm summers and cold, snowy winters. The mean annual temperature is approximately 1.5°C. The mean summer temperature is 14°C and the mean winter temperature is -11°C. The southern margins of the ecoregion exhibit a warmer, cool temperate climate. The mean annual precipitation ranges from 800 mm in the northwest to 1000 mm near Quebec City. Between Quebec City and the Saguenay River-Lac Saint Jean area to the north, the mean annual precipitation ranges 1200-1600 mm. This ecoregion is classified as having a low to mid-boreal ecoclimate. Its mixed forest is characterized by stands of white spruce, balsam fir, paper birch, aspen, and, in some cases, pure stands of trembling aspen. Black spruce and balsam fir occur on wet, poorly drained sites, whereas strips of tamarack are found on colder, wet sites. Composed mainly of massive Precambrian granites and gneisses, this ecoregion is incised by numerous, southward-draining rivers through undulating highlands, creating a mountainous appearance where relief is commonly about 300-600 m. The Jacques-Cartier massif region rises abruptly above the St. Lawrence River like an upheaved dome dominating the surrounding uplands. This part of the region includes some of the best timberland in Quebec and provides habitat for moose, black bear, and small mammals. Much of this old erosion surface lies at about 600 m asl with scattered summits reaching 900-1200 m asl. Surficial deposits are composed mainly of varying thicknesses of till and fluvioglacial sediments. Humo-Ferric Podzols are the dominant soils, and significant inclusions are Ferro-Humic Podzols, Dystric Brunisols on drier, coarse-textured outwash, and Mesisols on fen-bog sequences. Forestry, hunting and trapping, recreation, tourism, and some farming (less than 2% of the ecoregion) are the principal land use activities. The major communities include Gatineau, Maniwaki, Saint-Jérôme, and Shawinigan. The population of the ecoregion is approximately 675 600.
This ecoregion is part of the Boreal Shield ecozone.