DENVER (AP) — All 400 tickets were sold within 12 hours for a one-day, roundtrip ski-train excursion from downtown Denver to Winter Park, according to spokesmen for the resort and Amtrak.

The response helps build the case for resuming a regular alternative to increasingly congested roads, they said Thursday.

READ MORE: Delayed Start: Aurora Public Schools To Start Classes On Monday An Hour Later In The Spring

But Amtrak spokesman Marc Magliari added that a number of questions would have to be answered first, including how often service would run, how much it would cost and whether enough rail cars would be available given that ski season parallels several busy holiday travel periods.

The Colorado Department of Transportation “would definitely welcome alternative ways for people to travel to the mountain corridor,” agency spokeswoman Amy Ford said in an email Thursday. “Every bit helps to manage the I-70 corridor.”

The $75 tickets — half price for up to two children traveling with an adult — for the March 14 train trip marking Winter Park’s 75th anniversary sold out Wednesday. No more trips are scheduled this winter.

The Winter Park Express will leave at 7 a.m. from Denver’ s Union Station, which reopened to great fanfare last year after a major renovation project. It will deposit skiers steps from the lifts and return to Denver at 6:15 p.m.

Skiers’ “last run can end, they can pop off their skis and get right on the train,” Hurlbert said.

READ MORE: Some Evacuations Ordered For Miners Candle Fire Near Dumont

A private train used the same Winter Park station, now owned by Denver’s Regional Transportation District, from 1940, when the resort opened, until 2009. Insurance and other costs doomed that regular service, Hurlbert said.

RTD and Union Pacific, which owns the tracks, would have to be involved in plans for more runs, Amtrak’s Magliari said.

“The fact that the train sold out in less than 12 hours shows there’s great interest,” Magliari said. But “It’s too early to say what the service pattern might be next season. There’s a long way from here to there.”

Still, Magliari said, “this excitement is kind of hard to bottle up.”

By Donna Bryson, AP Writer

MORE NEWS: No Restrictions Yet, But Denver Water Customers Should Be Water Wise This Winter To Avoid Them

(© Copyright 2015 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)