Todd,
TransDEM is the best way to get what you want, and basically the only way for accurate terrain. There is a bit of a learning curve, but once you work out your routine, it's not so bad. I do recommend going through the tutorials, and I put together a quick guide, which I can send you. PM me and I'll send you the link.
The National Geologic Survey server unfortunately has gone through multiple changes since I did the quick guide, which actually is the process that I use for handling the TransDEM data. That part has to be rewritten, but I have some notes on that which I can send you as well.
On another note:
Your TS12 isn't showing as registered. Ensure you have entered in your CD-key (serial number) into your My Trainz account, which is the same one used to create your login here. You also need to login into TS12 and Content Manager using the same account, otherwise, things will get weird and people will keep bugging you about not being registered.
If you've already registered, purchased through Steam, or have used another account for TS12, you need to contact the helpdesk. The link is at the top of the forums. They can assist you.
Welcome to Trainz and the forums. A whole new world awaits you.
