All that bright part up to the north, with the black spots on it, is Canada.

The black spots are forests.

That long white line to the left is the Rockies.

You see they're all bright at the north, and as you go south you only see a few bright dots.

Those are the snow-peaks.
"Those long thin white lines in South America are the tops of the Andes, and the big, dark patches to the right of them are the forests and plains of Brazil and the Argentine.