On a very damp May 5, 2017, in Port Huron, Michigan, the drawbridge over the Black River is raised. This view is looking southward, with warehousing on the left and Domtar Paper on the right.  This line runs from the GT yard in Port Huron up to the other Domtar plant, which is just north of the Bluewater Bridge.  The line is used daily, and typically seems to see short trains of 2 to 6 cars with a GP38 providing the power. 

This picture looks north from the River Street crossing, showing the raised drawbridge from the other side.