I have been told that the best access to Glacier Park is via Canada where they have winter tours by "Ice Buggy" across the glaciers. They also offer transportation to the US. In the winter there are Amtrak stops and in the summer there are 3. Also, Amtrak will make a special stop at any time at the Walton Inn. This is a flag stop for pickup and a prior notification for anyone with reservations at the inn.