Traveling on Amtrak's California Zephyr is an almost cinematic journey into the American West. Starting in Chicago, westward-bound passengers on the doubledecker train roll across the prairies of Iowa and Nebraska, through the towering red ridges of the Colorado Rockies, up the ascending plateaus of Donner Pass, until hitting the Pacific Ocean and the end of the line in San Francisco.

(Joe Raedle/Getty Images)

(Joe Raedle/Getty Images)

The California Zephyr is Amtrak's second longest passenger rail service. Stretching 2,438 miles, the full trip can be done in either direction in just two days and two nights. But, as many Zephyr alums will advise, take your time. On this trip, the going is more important than the getting there.

This route is just one of Amtrak's many long-distance railways connecting the contiguous United States. But these sightseeing ventures are a drain on the business, often accounting for the majority of the company's losses. And if President Trump's proposed budget gets congressional approval, the long-distance routes will be eliminated altogether and the for-profit company, which receives billions in federal funding, would focus instead on the high-traffic Northeast corridor lines.

Below, a window into the American frontier from the tracks. Enjoy it while you can:

(Joe Raedle/Getty Images)

(Joe Raedle/Getty Images)

(Joe Raedle/Getty Images)

(Joe Raedle/Getty Images)

(Joe Raedle/Getty Images)

(Joe Raedle/Getty Images)

(Joe Raedle/Getty Images)

(Joe Raedle/Getty Images)

(Joe Raedle/Getty Images)