This photograph postcard from 1912 shows the Thomson Dam area between Carlton and Thomson. The bridge is the automobile and footbridge over the St. Louis River. The dam is in the background. The buildings are part of the St. Louis River Slate Brick Company Street and Road Macadam. According to the book "Carlton Chronicles," published by the Carlton County Historical Society, the slate brick plant was built by Jay Cooke interests in the 1890s. The plant used waterpower to grind slate into mud which was made into what was seen as a superior brick. The "Street and Road Macadam" part of the pla...