Witten's 4-foot module features an HO scale model of the California Zephyr and comes complete with mountain landscape, buildings, trees, people and other accessories.

In his basement, however, he has a much more elaborate setup that sends trains through mountain tunnels, past sheep ranchers, across a fishing stream, through towns and a railroad yard. He's been working on it for about 10 years now, says Witten, "ever since I retired." But he's about ready to tear down the mountain section and rebuild it, he adds. He didn't get the interior of the tunnels quite right, and trains tend to derail. He has to go down under and up inside to fix it, "and I'm getting too old for that."

Besides, he says, most of the fun is the working on a layout. It's never completely done.

True, says Murphy, who is currently "between layouts" because "every time I've got one up and going just how I wanted it, we've ended up moving, and I had to take it down or sell it off." But he's kind of itching to get going again. It appeals on so many levels, he says. "There's something for carpenters and electricians and artists. It's fascinating."

Modern technology has brought some changes to scale modeling, Murphy notes. For one thing, most trains now run with a "digital command control" system similar to a remote control. "It means you don't need all those wires anymore." Plus, you can control multiple trains on the same track.

It's exciting, but it can add to the expense. Whereas some of the old engines sold for about $35 to $60, new DCC-equipped ones can run as much as $300 to $400. "A lot of people put in their own electronics to save money," he says.

Another technological addition is sound chips. "Until a couple of years ago there was no sound, but that has brought a whole new dimension," says Murphy. Sound chips can simulate the chuff-chuff of a steam engine or the whistle of a locomotive or add other realistic noises to the operation.

Witten has also had fun with a "spy-cam," a tiny video camera he mounts on his train that hooks to a television monitor to provide an engineer's-eye view of the world.

In addition to his train operation, Witten has collected a lot of memorabilia from railroads: photographs, menus and dishes from dining cars, lanterns and such. "My father was a conductor on the Union Pacific, so I grew up with trains in my blood." His layout, he says, is a homage to his father.

His favorite part is "the scenic work. I love trying to make it look as real as possible, with the plants, the gravel." No detail is too tiny to overlook. He creates his own little decals, adds photographic backgrounds to store windows, builds tiny ladders for workers. A lot of modelers also like to "weather" their trains to make them look more like those you see on the rails, and they develop methods to add age and character.