Hallo,
this is going to be a great nice route!! Keep on going. It remembers me well to the beginnings of my Milwaukee Road Avery-Drexel route (available within TS2010). Per haps you will not be able to stay using water to simulate the rivers, especially if it gets into the narrow valleys. One day, I started to create a set of special splines of different size to create all the many creeks and rivers as required by the real thing.
Also you should think about change over to TS2010. Speed trees would provide a much better environment and this would support all the work you do much better than the trees you use not. It seems to me you are using tree ground cover splines to get the woods onto the many slopes you have. At the beginning of my Milwaukee Road project, I used to attempt the same. But soon, I changed over to single tree objects as it performs better. One thing, it just looks better, another thing is that single tree objects works better in the narrowness of the valleys.
In addition to this, you could keep yourself a backdoor open by using single trees. If you would use the very nice looking trees made by “Jankvis” in TS2009, you could later change over to speed trees in TS2010 by using the replacement tool.
That’s some thinking from me, just to chare experiences.
But anyway, this route will be grate to look at it and to play with it. I worked at the Milwaukee Road Avery-Drexel about four years time getting the route completed as well as creating all the needed special objects for buildings, tracks, bridges, tunnels, trolley wires and last but not leased the special locos and the freight cars. I hope you can make it in less time ;-)
Your’s TUME