Amtrak's service alerts have been littered with delays and reroutes (and annulments) on the Zephyr recently, mostly between SLC and Denver. Some have been due to track work by UP. The problem now is a fire in Glenwood Canyon that is also threatening Glenwood Springs, CO, itself. [
inciweb.nwcg.gov]
Another, larger fire to the west is also active near Grand Junction, but not directly affecting the railroad.
I don't have a customer account at UP, so I can't tell whether they have any notices out about the area.