Log driving is a means of moving logs (sawn tree trunks) from a forest to sawmills and pulp mills downstream using the current of a river. It was the main transportation method of the early logging industry in Europe and North America. History When the first sawmills were established, they were usually small water-powered facilities located near the source of timber, which might be converted to grist mills after farming became established when the forests had been cleared. Later, bigger circular sawmills were developed in the lower reaches of a river, with the logs floated down to them by log drivers. In the broader, slower stretches of a river, the logs might be bound together into timber rafts. In the smaller, wilder stretches of a river where rafts couldn't get through, masses of individual logs were driven down the river like huge herds of cattle. "Log floating" in Sweden (timmerflottning) had begun by the 16th century, and 17th century in Finland (tukinuitto). The total length of timber-floating routes in Finland was 40,000km. The log drive was one step in a larger process of lumber-making in remote places. In a location with snowy winters, the yearly process typically began in autumn when a small team of men hauled tools upstream into the timbered area, chopped out a clearing, and constructed crude buildings for a logging camp. In the winter when things froze, a larger crew moved into the camp and proceeded to cut trees, cutting the trunks into lengths, and hauling the logs with oxen or horses over iced trails to the riverbank. There the logs were decked onto "rollways." In spring when snow thawed and water levels rose, the logs were rolled into the river, and the drive commenced. To ensure that logs drifted freely along the river, men called "log drivers" or "river pigs" were needed to guide the logs. The drivers typically divided into two groups. The more experienced and nimble men comprised the "jam" crew or "beat" crew. They watched the spots where logs were likely to jam, and when a jam started, tried to get to it quickly and dislodge the key logs before many logs stacked up. If they didn't, the river would keep piling on more logs, forming a partial dam which could raise the water level. Millions of board feet of lumber could back up for miles upriver, requiring weeks to break up,