Amtrak is now running in Glenwood Canyon (Colorado) again, according to this article, but slowly because of problems with debris on the tracks.
https://www.aspentimes.com/news/union-pacific-amtrak-resume-train-service-through-glenwood-canyon/
https://www.aspentimes.com/news/union-pacific-amtrak-resume-train-service-through-glenwood-canyon/