The best way to navigate Canada’s mighty St. Lawrence river? By cargo ship, of course—Tim Johnson traces a shipping route that delivers essential goods to remote First Nations and Québécois Canadians.

At this point, here on the south shore, it seems a little ridiculous to call the St. Lawrence a river.

One of Canada’s great waterways—the one that links the Great Lakes with the North Atlantic and brought European explorers like Jacques Cartier and Samuel de Champlain deep into the heart of this part of the New World—it cleaves a massive divide into two provinces on the eastern end of the country. And when the mighty St. Lawrence reaches Rimouski, in Quebec’s Bas-Saint-Laurent region, you can scarcely see across it.

Sailing east from here, it only gets bigger, and wider, and stronger, eventually emptying into a gulf of the same name. But across on the north shore, the population thins out, just a string of small villages separated by forest and bush so complete it could swallow you whole. Living in relative isolation, each one of these communities occupies its own little world.