Man, that is too cool! Trains were my first love, before rockets. I always wanted a model railroad but always lacked either the space or the money, or both. Finally started to build a narrow gauge layout in my garage with hand-spiked rails and everything. Didn't get very far though before we needed to put on a room above the garage, and the whole thing had to be torn out for the remodel. About that same time I started getting into high power rockets and the rest is history.
I still have the framework and some of the basic roadbed of the model railroad stored along a wall in the garage, but now I doubt I'll ever do anything with it. Since the garage is also my workshop and paint area, it's just way too dusty and cluttered to ever be suitable for a decent scenic layout. Plus my eyesight's not what it used to be.
BTW, there are some very nice large scale garden railroads up in Oregon. My dad and I toured some of them when I was visiting a while back.
Also, if you ever get a chance to come to Nevada, check out the Nevada Northern Railroad museum in Ely, NV. Real railroad stuff, not models. They have some beautiful old steam engines and wooden coaches, lots of old time equipment, coal tower, the whole works.
San Diego has a nice railroad museum too, in Campo out in the east county. Several years ago my wife and I rode the "dinner train" there -- great fun! You board the train about 6pm, and have a gourmet meal while the train rolls through the country side.