The acquisition will take place over a three-year period, with Canfor acquiring a 25 per cent interest in the lumber producer during the first phase.
Scotch is headquartered in Mobile Alabama and has sawmills in Mobile, Fulton and Jackson, Alabama.
The company makes lumber products from Southern yellow pine and has a production capacity of 440 million board feet.
The deal was first announced at the end of May.
Canfor has operations in B.C., Alberta, Quebec, and North and South Carolina. It also owns a 50.2 per cent interest in Canfor Pulp Products Inc. (TSX:CFX).