The Great Train Expo, an exhibit to delight youngsters and bring out the child in the man, stopped in Santa Rosa over the weekend.

The sound of miniature train whistles and chugging steam engines from operating model railroads echoed throughout Grace Pavilion at the Sonoma County Fairgrounds.

The show included exquisitely tiny railroads, larger "HO" and "O" models, and even a battery-operated trackless train to ride on.

"It's a boy thing. Look at all the little boys around," said Chris Daniels, whose sons, Willy, 7, and Correy, 2, reacted in wide-eyed wonder Sunday at the model trains.

"It's that power and speed thing," he said of the appeal. "They love fast, powerful things. Trucks too. They're typical boys."

Daniels said his father used to bring him to model train shows.

"I'm carrying on the tradition," he said.

But adults also were entranced by the little trains, complete with shrunken towns, miniature bridges and trestles.

"It's fun," said Steve Lewis about why grown men like himself play with model trains.

The retired economics professor and member of the Coastal Valley Lines club explained that "there's all kinds of little sub-hobbies: doing the scenery, taking the engines apart and making them run better."

"Model trains are the largest hobby in the world," said Anton Seckler of San Mateo. He conducts European tours for train enthusiasts who fancy the real thing, as well as visiting what he described as the biggest and most intricate model railroad in the world, in Hamburg, Germany, featuring 1,000 running trains.

"The appeal for me is the model itself, the construction and detail, and of course operating the trains," said Brad Squires, also a member of Coastal Valley Lines and the Redwood Empire Garden Rail Society.

"The whole idea is to make it as realistic as possible," he said, noting the detail of the models at the Expo, including Santa Rosa landmarks.

One was a meticulous replica of the Emporium store that opened in Coddingtown shopping center in 1962. Another was the red, historic Fountaingrove Round Barn.

Squires, 61, said each train show is different because the space allotted dictates the size of the train display.

"It's like playing a guitar. It's different every time, depending on where you put your fingers.

"I've been in the hobby since I was a small boy. I got my first train set when I was 7 or 8," Squires said, explaining how he got hooked.

The appeal seems timeless.

Nicole Gulick, a Sonoma mother, was holding her 22-month-old son, Matteo, also transfixed by the moving miniature trains.

"He's a huge fan of Thomas the Train. I knew he'd really love this," she said.

While there is a preponderance of boys who like trains, Allie Foster, 13, was one of the girls at Sunday's show.

"I love trains," she announced.

Allie started constructing "modules," or segments of track with scenery, when she was 6.

"It always kind of fascinated me," she said as she showed off the different modules she has made, including a Hawaiian beach scene that the trains pass through.

"It's one of the places I think about. It relaxes me when I'm stressed," said the seventh-grader.

Plenty of merchandise was also on sale, including all models of small engines and railroad cars.

Daniels has a 70-year-old Lionel train set he inherited from his uncle. "I'm always looking to add to it," he said, explaining he is on the lookout for spare parts, like a mini-rubber conveyor belt for his coal loader.

You can reach Staff Writer Clark Mason at 521-5214 or clark.mason@pressdemocrat.com.