You know, fatman, what you speak of sounds more like one of those RailRoading town dio's, in HO scale. There exist MANY sources for obtaining practically any type realism you'd care to include.
I've stood and looked through the selection of HO scale dio material at Hobby Lobby, and pondered the possibilities of building a dio of a section of a Civil War battlefield, maybe about 2 scale acres of real estate (I must do the figures in 1/72nd scale, as in the old MPC Civil War figures kit), with a forked creek running across it, a few buildings ruins (as if on the edge of a town), trees, weeds, rail fence, etc etc...
One could incorporate and endless number of specific scenes in something like that, the same as you could with your town dio (including electronics).
If you built it on a plywood base (you could use Styrofoam to make ground contours), when it's done, get some Plexiglass sections cut (down at Lowe's), some rubber cement, and make a pretty decent protective case that would be attached to the base by "O" ringed screws.
Good luck and keep us posted.
Take care,
Frank