I'm probably one of the first to ask for a Pere Marquette Route but I personally love the PM Berks and Mikados and I think they'd be great additions for spirit of steam. I'd like the route to take place in 1946, just after World War 2. The locomotives would consist of the PM N, N-1 Berkshires and MK-2 Mikados
I personally think that this is a good idea, but instead have a part of the (correct me if I'm wrong) Detroit - Grand Rapids route. That way we can also operate their only streamliner.
I did it to only Lansing because I was worried that the route would be too long but I wholeheartedly agree with you.
