A quick peek via Google Earth shows the railroad's swing span bridge has been removed south of the depot.
When the C&O wanted to abandon the line to Petoskey, it was offered to Michigan Northern for $1, if MIGN acquired the bridge and some track to the south of it. It was a rational offer by the C&O. They were on the hook to remove all of the bridge and its approaches down three feet below the mudline. This Coast Guard requirement was due to the canal between Lake Michigan and Lake Charlevoix being a navigable waterway.
MIGN did run trains briefly on the line but a right of way landslip along the shore of Lake Michigan put an end to operations.
I think (but am not sure) the State of Michigan bought the line and contracted with MIGN to operate on it.