HUDSON, WI (WTAQ) - The first work on the new bridge over the St. Croix River near Stillwater involved the drilling of test shafts into the river Thursday. Load tests will be conducted there over the next two months. Bridge designers are determining just how much weight the ground below the river will bear. The new four-lane bridge will have six sets of piers in the water, with a seventh set on land on the Wisconsin side. Construction work officially starts next year and should finish in 2016. The new bridge will replace the aging Stillwater Lift Bridge and will connect Oak Park Heights, Minnesota, with St. Joseph Township, Wisconsin.