The Ottawa River timber trade, also known as the Ottawa Valley timber trade or Ottawa River lumber trade, was the nineteenth century production of wood products by Canada on areas of the Ottawa River destined for British and American markets. It was the major industry of the historical colonies of Upper Canada and Lower Canada and it created an entrepreneur known as a lumber baron. The trade in squared timber and later sawed lumber led to population growth and prosperity to communities in the Ottawa Valley, especially the city of Bytown (now Ottawa, the capital of Canada). The product was chiefly red and white pine. The industry lasted until around 1900 as both markets and supplies decreased.
The industry came about following Napoleon's 1806 Continental Blockade in Europe causing the United Kingdom to require a new source for timber especially for its navy and shipbuilding. Later the U.K.'s application of gradually increasing preferential tariffs increased Canadian imports. The first part of the industry, the trade in squared timber lasted until about the 1850s. The transportation for the raw timber was first by means of floating down the Ottawa River, proved possible in 1806 by Philemon Wright. Squared timber would be assembled into large rafts which held living quarters for men on their six week journey to Quebec City, which had large exporting facilities and easy access to the Atlantic Ocean.
The second part of the industry involved the trade of sawed lumber, and the American lumber barons and lasted chiefly from about 1850 to 1900-1910. The Reciprocity Treaty caused a shift to American markets. The source of timber in Britain changed, where its access to timber in the Baltic region was restored, and it no longer provided the protective tariffs. Entrepreneurs in the United States at that time then began to build their operations near the Ottawa River, creating some of the world's largest sawmills at the time. These men, known as lumber barons, with names such as John Rudolphus Booth and Henry Franklin Bronson created mills which contributed to the prosperity and growth of Ottawa. The sawed lumber industry benefited from transportation improvements, first the Rideau Canal linking Ottawa with Kingston, Ontario on Lake Ontario, and much later railways that began to be created between Canadian cities.