I understand that half of the population lives within 50 miles of the Canada-US border. We seem to be almost the same group of people as they are--DELIGHTFUL folks. Of course, I was with the tourist folks and they WOULD be nice to us.
The population of Canada is situated where the arable land is and where navigable rivers are. For the most part, Canada was settled before people moved en mass to the cities and society everywhere was primarily agrarian - farmer folk.
The arable land is along the southern border. Further north is solid bedrock with a thin layer of soil on top where our boreal forest grows. In this region forestry and mining is are major economic activities, but agriculture is impossible. There are small single industry towns and cities in that area, but not great metropolises. Population is very sparse with long empty spaces in between.
Further north of that is tundra and permafrost where it`s too damned cold for anything to grow.
Further north still is polar ice caps, also not conducive to large populations. About the only thing it`s good for is polar vortexes. ;-p