The Colorado Department of Transportation has issued a request for information about what train vehicles might be available for proposed passenger service between Denver and Craig.

The request isn’t a solicitation for bids or meant to result in a contract or order for equipment, but rather an effort to understand what’s available.

“Let’s get rolling to provide more transportation options for Coloradans and visitors who want to explore, live and work in our world-class mountain communities and local economies. I look forward to the results to help make convenient mountain rail a reality,” said Colorado Gov. Jared Polis.

Shoshana Lew, executive director of CDOT, said the request is a first step to understanding what technology could meet the needs of mountain conditions. “We’re interested in factors like cost, safety technology, reliability and the use of energy efficiency options and clean power.”

Mountain rail service became a more likely possibility in recent months because of decreased coal train traffic on Union Pacific lines and an opportunity to host more passenger trains. UP lines serve the California Zephyr and Winter Park ski trains, but there’s capacity for service from Denver to Steamboat Springs, Hayden and Craig,

In addition, Congress plans to earmark $66 billion for passenger rail service through the Infrastructure Investment and Jobs Act. Because the Denver-to-Craig service would only require minimal track and safety improvements, CDOT expects the mountain rail project would constitute a candidate for federal funding.

The Colorado Transportation Commission approved $5 million in state funding for CDOT to study the mountain rail route.