Conversation so far:
What is significant about the fur trade in Canada and Harold Innis?
Harold Innis's interest in the relationship between empires and colonies was developed in his classic study, The Fur Trade in Canada: An Introduction to Canadian Economic History.
What was in Harold Innis' classic study, The Fur Trade in Canada: An Introduction to Canadian Economic History?
Harold Innis documents how the interplay of geography, technology and economic forces shaped both the fur trade and Canada's political and economic destiny.
Are there any other interesting aspects about this Harold Innis article besides the fur trade and Canada's political and economic destiny?
Harold Innis argues that the fur trade largely determined Canada's boundaries.

Question: What was his reasoning?
Self-contained rewrite: What was Harold Innis' reasoning that the fur trade largely determined Canada's boundaries?