Based on the cars that looks more like the Local that goes north of Flat Rock to River Rouge. The Rockwood local would have a lot of two bay covered hoppers and maybe an empty CenterBeam or two. Do the Flat Rock-Rockwood and Toledo-Rockwood Locals exchange cars?
Anyway, CN switches a lot of lumber loads to Nichols on River Rouge.
I don't know where the plastic pellet covered hoppers are from.
PatC created a monster, 'cause nobody wants to see Don Simon no more they want AARR I'm chopped liver, well if you want AARR this is what I'll give ya, bad humor mixed with irrelevant info that'll make you roll your eyes quicker than a ~Z~ banhammer...