Coast to Coast to Coast
Canadian geography in 24 lessons, with Nora Beaulieu
Module 7 · Regions up close · Lecture 20

The Prairies: three steps, a grid and a dry triangle

Manitoba, Saskatchewan and Alberta: the Interior Plains rising in three steps, the Dominion Lands survey grid, the grassland that is mostly gone, grain, potash and oil, and the coldest and driest capitals. Skill: reading the survey grid on a satellite image.

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Test yourself

1. Which province holds the largest share of Canada's farmland, in the twenty twenty-one Census of Agriculture?
Saskatchewan holds about thirty-nine per cent of Canada's farmland, with Alberta second at thirty-two.
2. On the lettered map, what are the three prairie steps, from west to east?
The Interior Plains step down from the Alberta Plateau in the west to the Manitoba Plain in the east.
3. Where are all ten of Canada's potash mines?
Natural Resources Canada counts ten potash mines, all in Saskatchewan, about a third of the world's supply.
4. What is Winnipeg's January mean temperature in the climate normals for nineteen ninety-one to twenty twenty?
Winnipeg's January mean is minus sixteen point three degrees, the coldest of the provincial capitals.
5. In what year was the Dominion Lands Act passed, setting up the Prairie survey grid?
The Dominion Lands Act of eighteen seventy-two set up the townships of thirty-six sections and the quarter-section homestead.
Transcript

A gravel road allowance near Davidson, Saskatchewan, ten at night in late August, the combine lights sweeping a wheat field. Harjinder Sidhu, who goes by Harry, is forty-seven, a Punjabi-Canadian grain farmer. His summer hire, Emily Ross, nineteen, from Regina, has just learned that the dead-straight road she drives every day was laid out by surveyors in 1872.

So here's the question. Why does the Prairie map look like graph paper, and why is the land inside those squares so different from one corner to the other?

The shape first. The Interior Plains rise westward in three broad steps, the Manitoba Plain, the Saskatchewan Plain and the Alberta Plateau, on flat-lying sedimentary rock, up to the Cypress Hills at 1,392 m. In Environment Canada's climate normals for 1991 to 2020, Winnipeg has the coldest January of the capitals, minus 16.3 degrees, and Regina is the driest, 390 mm a year.

Under the Dominion Lands Act of 1872, the Canadian Encyclopedia says, the West was surveyed into townships of thirty-six sections, each a mile square, and a settler could claim a quarter-section, 160 acres, for a ten-dollar fee. First Nations were assigned reserves under the treaties and the Métis received scrip. Crown-Indigenous Relations counts eleven Numbered Treaties, 1871 to 1921, from Lake of the Woods to the Rockies.

Today Statistics Canada puts Alberta at 5.1 million, Manitoba at 1.5 million and Saskatchewan at 1.3 million, as of April 2026. The 2021 Census of Agriculture gives Saskatchewan 39% of Canada's farmland and Alberta 32%. The 2025 harvest was the biggest ever: 40 million tonnes of wheat and nearly 22 million of canola.

Under the fields is more. The Canada Energy Regulator says Alberta pumped 84% of Canada's oil in 2023. Natural Resources Canada calls Canada the world's largest potash producer, with all ten mines in Saskatchewan, about a third of world supply in 2024, and Saskatchewan is the only province that mines uranium. Manitoba's electricity, meanwhile, is 96% hydro.

Find it on the map. This is a satellite image of the fields around Davidson, public-domain Landsat from the United States Geological Survey, beside the same roads from OpenStreetMap. Each square is one section, a mile on a side, about 1.6 km. Count six across and six up: that block of thirty-six is a township. The survey lines run north and south, so on the Prairies the map and the compass agree.

Let's change one fact. Slide the dry belt geographers call Palliser's Triangle 300 km north. Now the driest land sits on the Saskatchewan River, and the wheat belt lands on the Shield's thin soil. Davidson becomes ranch country, the grain elevators move to the parkland, and Emily's straight road runs through grass instead of wheat.

The mistake people make is calling the Prairies flat and all the same. The land climbs step by step from the Manitoba lowland toward the foothills, the Cypress Hills stand higher than anything in Ontario, and Parks Canada says only a small portion of the native grassland remains, most of it long since ploughed. Snowy Winnipeg and dry Regina are five hundred kilometres apart.

Here's the rule, in one breath. Three steps rising west, one grid a mile square, and under it grain, potash and oil, in a land that is dry in the south and cold everywhere in January.

This week, open the satellite layer on Toporama anywhere on the Prairies, find the one-mile grid, and count ten sections along a road. Then work out how many kilometres you have travelled.

Next time, British Columbia: three mountain belts, a rain shadow, and a coast that shakes.

← Lecture 19: Ontario: the lowlands, the Shield and the far northLecture 21: British Columbia: mountains, rain and the ring of fire →
Free, independent course. Not an official resource of Immigration, Refugees and Citizenship Canada or of any Ministry of Education. Facts are from Statistics Canada, Natural Resources Canada, Environment and Climate Change Canada and other government sources, as dated in each lecture; figures change, so check the source for the latest. Maps are drawn from Natural Earth (public domain); photographs are from Wikimedia Commons under open licences, credited on the maps and photos page. Nora Beaulieu is an AI-generated presenter with a synthetic voice. Course content © 2026.