Just after 480 children and their parents were served cookies and hot chocolate aboard the Polar Express train on Saturday night, Mrs. Claus boarded.

Riding the Heber Valley Railroad Christmas Train, the group set off at dusk on a trip to see Santa at the North Pole. Now in its ninth year, the tradition, based on the best-selling children's picture book by Chris Van Allsburg, is so popular that even adding four new coach cars has not slackened demand. More than 20,000 of the 21,700 tickets available for 48 train trips scheduled this season have been spoken for -- and the rest are expected to sell out by mid-week, railroad officials said.

As the train clacked and moaned, Mrs. Claus greeted each of the children aboard and handed out a recipe for chocolate chip cookies made with all the usual ingredients and a few extra, including a gallon of joy, a reindeer's shy wink and fairy dust colored pink.

"Did you know you are wearing Santa's favorite colorfi" Mrs. Claus said to one child dressed in red pajamas. "Have you been doing homework this yearfi" she said to another. "Are you very good at mathfi"

After Mrs. Claus exited the coach car, elves passed out copies of the Polar Express book so the children could follow along as a storyteller read the book aloud. Just as the story ended, the train pulled up to a lighted Santa's Village at the North Pole which also bore some resemblance to the shore of Deer Creek Reservoir.

With jingling bells, Santa boarded the train to oohs and ahhs, laughter and clapping. Flashbulbs popped and children beamed as he visited with each, laughing merrily and handing out silver bells, just as in the book. Before moving on to the next car, Santa led a round of Jingle Bells, saying the children needed to do some caroling.

The bells were not the only gift on the train. On Tuesday, just in time for the Polar Express runs to begin, one of the four new coach cars reached the end of a six-month restoration led by a volunteer master cabinet maker, Kerry Ellertson of Midway.

Ellertson, who first worked on the railroad in 1970 and returned four years ago as a night conductor, hand-crafted much of the extensive woodwork on the coach car as a gift to the railroad. He will spend next year working on the three remaining new cars.

"I took this on because they would have had to hire someone and it was a lot of work," he said, noting that he and other volunteers installed new floors, ceilings and windows, and all the seats were sandblasted, painted and reupholstered. "I have always loved the railroad and I want to see it succeed."

Ellertson's work saved the nonprofit railroad tens of thousands of dollars, said Craig Lacey, executive director.

Chris and Kelly Steele of Park City brought their two children, Keegan, 9, and Collin, 7, on the ride with two cousins and family visiting from New York.

When she called the railroad to get information on the ride, "the lady on the phone actually had me in tears telling me about it," Kelly Steele said. "The kids had a ball. We brought them here as a surprise Christmas experience."

Adam and Lyndi Vance of Saratoga Springs brought their five children, ages 8 to 8 months. Last year they were unable to get tickets to the sold-out train so this year they bought tickets "months ago," they said on Saturday.

To get in the mood for the experience, the family watched the Polar Express movie on Friday night and listened to the soundtrack on Saturday, they said.

Susan and Mike Sisson of Bluffdale brought their five children, two grandparents and a great-grandparent on the excursion.

"I had heard about it and wanted to come and thought it would be a great kick-off to the Christmas season -- and the kids love the book," she said.

For reservations on the Polar Express call (435) 654-5601 or visit www.HeberValleyRR.org.

This story appeared in The Daily Herald on page C1.