Train consists are not something widely available to railfans. Sometimes one might get tossed out after a run is completed, or maybe somebody could have found some in a burn barrel. But it's certainly nothing that any OFFICIAL source would still have.
Are you talking ANY train, or a specific one? You might be able to piece some info together by watching video - if a block of XYZ RR covered hoppers frequently shows up on COJ32 you may be able to learn where those cars came from and went to. But then just a car type and reporting marks don't help in figuring origin/destination.
LV has an active retirees organization. Your best bet might be to contact them and see if you can ask one of their guys directly.
Care to share which particular train and what overall info you're looking for?