the napoleonic wars and the continental blockade cut off, or at least reduced the baltic trade so the british looked northwards to the colonies that had remained loyal and were still available. the industry became concentrated in three main regions. the first to be exploited was the saint john river system. trees in the still almost deserted hinterland of new brunswick were cut and transported to saint john where they were shipped to england. this area soon could not keep up with demand and the trade moved to the st. lawrence river where logs were shipped to quebec city before being sent on to europe. this area also proved insufficient and the trade expanded westward, most notably to the ottawa river system, which, by 1845, provided three quarters of the timber shipped from quebec city. the timber trade became a massive business. in one summer, 1200 ships were loaded with timber at quebec city alone, and it became by far british north america's most important commodity. it was from the money made in timber that the bank of montreal was founded in 1817.