This is an easy two-stage multi that requires minimal mathing. At the posted you will find a plaque with some information. Take the year the first sawmill was completed and divide by 1000. Now, to the meaningless coordinates below subtract that number from the north and add that same number to the west.
N 43 11.785 W 80 28.933
The final is a short drive away. Be sure to pull well off onto the shoulder of the road, and watch for traffic.