Go to this location:
www.uprr.com/aboutup/maps/attachments/elevations.pdf
It gives you a map of the Union Pacific system showing the high elevation points across their system. The CZ route spends more time and miles at high elevations than any other route. The information in the boxes showing location and elevation is mostly, but not entirely obvious.
First line: High Elev. - Railroad subdivision name - that is their name for this particular section of track as given in the employee timetable
Second line: elevation in feet above sea level (obviously)
Third Line: station name. Not necessarily a town, but name of the point as shown in the railroad employee timetable, which is usually town name, but may not be a very large one.
Fourth Line: Milepost location. Not necessarily the milage from starting point of the route of the train.
Points along the CZ route, beginning at Denver and going west:
First one, at Winter Park, Colorado, at the Moffat Tunnel itself, elevation 9,239 feet, 52.85 miles west of Denver. Highest point for any train on the Amtrak system. The pre-UP company was the Denver and Rio Grande Western.
Second one, at Summit Utah, one more reasons that D&RGW used to advertize their route as being "Through the Rockies, not around them" Milage here is from Denver by way of Pueblo, which was the original D&RGW route. It is about 180 miles longer than the current route.
Third one, at Hogan's Tunnel, Nevada: the pre-UP company here was Western Pacific. zero is at some point in the Bay Area, with miles through Stockton and the Feather River Canyon.
Fourth one, at Elko, NV: the pre UP company here is Southern Pacific, based on the milepost number shown. Zero is at Oakland CA. This point is in reality only something like 85 miles from the previous piont. SP was shorter, as its route out of the Bay Area was more direct. Don't know why this point is even shown. A note: Between Alazon, a point about 45 miles east of Elko, and Wells, a point near Winnemucca, the WP and SP operated as a paired track, making the two railroads function as if a double track railroad.
Fifth point, at Norden, California: This one is the railroad summit at Donner Pass. elevation 6,887 feet, milepost 192.50, from Oakland CA via Sacramento, the original transcontinental. The descent from Norden to Roseville is the largest change of elevation in one bite on any railroad in the US.
Right now there is something like 15 feet of snow on the ground in the vicinity of Donner Pass.
Now, if you come back east on the Sunset Limited, you will go through the lowest point on any railroad in the US as you go by thet Salton Sea, -205 feet at Forrum California, between Los Angeles and Yuma AZ.