The Rocky Mountain Rail Authority’s push to develop a high-speed intercity train network across Colorado will study spurs to Aspen, Steamboat Springs and Breckenridge but has eliminated a branch to Winter Park as too costly.

The authority has outlined about 600 miles of basic routes, potential stations and types of trains it will study, based on meetings with officials and planners from along the routes, chairman Harry Dale said Tuesday.

The authority is doing a $1.5 million feasibility study to determine whether a train system capable of traveling as fast as 125 mph can be financed and operated along the major east-west and north-south travel corridors of the state.

The skeleton map of the system shows a line going between Denver International Airport and Grand Junction, paralleling Interstate 70, and another stretching between Trinidad and Cheyenne, parallel to Interstate 25.

There are 17 major stations to be studied, with 27 secondary stations. Five potential spur lines emanate from the I-70 corridor to reach Aspen, Craig, Leadville, Breckenridge and Central City-Black Hawk.

“We want to have some ability to compare different scenarios,” Dale said. “These things are at least on the table for an initial look. We’re likely to refine and optimize them, hear what the issues are from local jurisdictions.

“We’ll probably end up with a recommended alternative reflecting a combination of what’s on the table. And if nothing is feasible, then at least we’ll know that.”

The study is to be finished by next summer. It is a step toward applying for designation as a federal high-speed rail corridor, which could help attract funding.

There is no overall price tag yet because the scope isn’t determined. But Dale said basic costs have been estimated at $2 million to $50 million a mile for on-grade construction, $50 million a mile for tracks on structures, such as bridges, and between $150 million and $200 million a mile for tunnels.

A possible tunnel under Cottonwood Pass to avoid going through narrow Glenwood Canyon would be nine miles long.

In addition to eliminating a Grand County branch to Winter Park, the group also eliminated diesel trains in the mountain corridor. They wouldn’t be able to maintain high speed while ascending the steep grades encountered crossing the Rockies. Trains include magnetic-levitation and electric-powered models in use in Europe and Asia.

What killed the Winter Park spur line for now is cost, Dale said. The short Grand County spur didn’t have enough ridership to pay the cost of boring a new high-mountain tunnel. Winter Park is on the west side of Berthoud Pass, and there are no planned destinations to the west to attract more riders.

“Our consultant said if we wanted to get to Grand County, we have to do either a parallel bore of the Moffat Tunnel or a new bore under Berthoud Pass,” said Dale.

“The possible cost didn’t seem to justify pursuing that as a viable option. We’re trying to get to the most significant markets at the least amount of cost – not that any of this is inexpensive.”