Amtrak has suspended rail service between St. Paul and the West Coast due to a major snowstorm and avalanches reported in Montana's mountain passes.

The once-daily westbound Empire Builder from Union Depot to Seattle, Portland and Spokane has been canceled for Monday and trains may not be rolling for days, said Amtrak spokesman Marc Magliari.

Amtrak is notifying passengers and will reschedule trips or offer refunds, Magliari said.

Eastbound Empire Builder trains from St. Paul to Chicago will operate as normal starting with Tuesday's 8 a.m. departure. On Monday, buses took passengers to Chicago, said Deborah Carter McCoy with the Ramsey County Regional Railroad Authority, which operates Union Depot.

On the upside, with the eastbound train originating in St. Paul, there will be an on-time departure, she said.

To accommodate westbound passengers with questions, Amtrak's Union Depot office will be open until 10 p.m.. Passengers also can call 1-800-USA-RAIL.

As of Sunday evening, winter storm Maya had dropped as much as 3 feet of snow in northwestern Montana with 1 to 2 inches per hour continuing. A blizzard warning was issued for Glacier National Park by the National Weather Service through Monday morning.

Trains were unable to get through Marias Pass on the southern boundary of Glacier National Park, forcing Amtrak to curtail service. Trains were being sent back to stations in Shelby and Whitefish, Montana. Eastbound trains were not departing from the West Coast, and Maglari said "it could be a lengthy disruption."

Amtrak operates on tracks owned by BNSF Railway. Freight trains also have been halted, said spokeswoman Amy McBeth.

There was no immediate word as to when the pass might reopen and rail service could resume, McBeth said.

"BNSF crews were prepared for and are actively working to mitigate avalanche debris and blowing snow that has reached the rail grade," she said. "We will resume operations through the corridor when conditions allow for the safe movement of trains."