Drive the Trans-Canada Highway from Vancouver to Montréal and the land keeps changing under you. First come snow-capped peaks and deep valleys, then a thousand kilometres of flat, open fields, then a seemingly endless stretch of pink and grey rock, lakes and forest, and finally gentle farmland dotted with towns. You have just crossed four of Canada's landform regions. Each one looks different because it is built from different rock and was shaped by different forces over very different lengths of time. Knowing the regions helps you explain where Canadians farm, mine, build cities and go hiking.
What makes a landform region
A landform is a natural feature of Earth's surface, such as a mountain, plain, plateau, valley or escarpment. A landform region (also called a physical region) is a large area where the landforms, the underlying rock and the way the land formed are broadly similar. Geographers tell regions apart using a few characteristics: relief (the difference between the highest and lowest points, or how rugged the land is), elevation (height above sea level), rock type (igneous, sedimentary or metamorphic), origin (how and when the land formed), drainage (how water flows across it) and soils.
| Region | Where | What it is made of and how it formed | What it looks like |
|---|---|---|---|
| Canadian Shield | A huge horseshoe around Hudson Bay: much of Quebec, Ontario, Manitoba, Saskatchewan, the NWT and Nunavut | Very old igneous and metamorphic rock, such as granite and gneiss, the worn-down roots of ancient mountains | Rounded rocky hills, thin soils, countless lakes, rivers and wetlands, boreal forest |
| Western Cordillera | British Columbia, Yukon and western Alberta | Young mountains pushed up and folded as tectonic plates collided; still active | Parallel mountain ranges, high peaks, deep valleys, plateaus; Mount Logan (5,959 m) is Canada's highest point |
| Interior Plains | Between the Cordillera and the Shield: Prairies, northeastern BC and the Mackenzie valley | Flat layers of sedimentary rock laid down in ancient seas | Flat to rolling land, deep fertile soils in the south, wide river valleys |
| Hudson Bay Lowlands | Around the southern shores of Hudson Bay and James Bay (Manitoba, Ontario, Quebec) | Flat sedimentary rock covering the Shield; land still slowly rising since the glaciers melted | Very flat, poorly drained wetlands and peatlands (muskeg), permafrost in places |
| Great Lakes–St. Lawrence Lowlands | Southern Ontario and the St. Lawrence valley in Quebec | Sedimentary rock (limestone, shale, sandstone) covered by deposits left by glaciers | Gently rolling plains, rich soils, the Niagara Escarpment; home to about half of Canadians |
| Appalachian Region | Atlantic provinces and southeastern Quebec | Very old mountains, formed hundreds of millions of years ago and worn down by erosion | Rounded hills and low mountains, rugged coastlines, fertile valleys such as the Annapolis Valley |
| Arctic lands: Arctic Lowlands and Innuitian Mountains | Arctic islands of Nunavut and the NWT | Lowlands of flat sedimentary rock; the Innuitian Mountains on Ellesmere and Axel Heiberg islands were folded much later than the Shield | Flat, cold, treeless plateaus and lowlands; rugged ice-capped mountains in the far north |
Shields, lowlands and highlands
It helps to sort the regions into three families. The Canadian Shield is the ancient core of North America. Lowlands (the Interior Plains, Hudson Bay Lowlands, Great Lakes–St. Lawrence Lowlands and Arctic Lowlands) are flat areas where layers of sedimentary rock were laid down on top of the Shield rock, often in shallow seas. Highlands (the Western Cordillera, Appalachians and Innuitian Mountains) are mountain regions created where tectonic plates pushed against each other. The big difference among the highlands is age: the older the mountains, the longer erosion has had to wear them down.
- Western Cordillera and Innuitian Mountains
- Formed tens of millions of years ago (the Cordillera is still rising in places)
- High, sharp peaks and steep slopes
- Earthquakes are common along the BC coast
- Appalachian Region
- Formed hundreds of millions of years ago
- Low, rounded hills after ages of weathering and erosion
- Earthquakes are rare and usually small
- Ontario has three landform regions: the Canadian Shield across most of the province, the Hudson Bay Lowlands in the far north and the Great Lakes–St. Lawrence Lowlands in the south.
- The Niagara Escarpment is a long cliff of hard dolostone (a limestone-like rock) running from Niagara Falls to the Bruce Peninsula and Manitoulin Island. Niagara Falls began at its edge near Queenston and still pours over its hard caprock, about 11 km upstream.
- Muskeg is waterlogged peatland. Lots of it covers the Hudson Bay Lowlands, one of the largest wetlands in the world.
- The Interior Plains are often called the Prairies in the south, but they continue north along the Mackenzie River to the Arctic Ocean.
Landform regions matter because they set limits and offer chances. The flat, fertile Great Lakes–St. Lawrence Lowlands, close to water routes, attracted farms, then towns and factories, and now hold most of Canada's largest cities. The Shield's thin soils kept farms away but drew mining towns such as Sudbury and Timmins. The Plains became one of the world's great grain-growing regions, while mountain valleys in the Cordillera channel roads, railways and towns into narrow corridors. You will see this link between land and life again and again in this course.