It can get cold on the train, so remember to bring a jacket and some comfortable clothes.

Thankfully, the train cars are air-conditioned in the summer. But that can also make them quite chilly, especially at night.

I came equipped with some thermal leggings and a puffy jacket.

Make sure to wear clothes that you're comfortable sitting in for long periods of time. And I recommend bringing a change of clothes (or at least an extra shirt) if you're traveling for multiple days.

The observation car fills up quickly, but you can find great views just below it.

Everyone wants to be in the observation car during the most scenic stretches of the Zephyr's route (especially through the Rocky Mountains), making it tricky to find a seat.

If it's full, head to the café car, which is right below the observation deck on the Zephyr. There are tables right up against the large windows, and you'll have almost as good a view as you'd get upstairs.

You have to buy something to sit there, but I thought it was worth it for a change of scenery.

It can be possible to get free hot water on the trains.

I realized on this journey that the café car had a supply of free hot water. You can bring your own foods (like instant ramen) or tea and just ask them to fill up your cup.

I saw several passengers doing so and wished I'd thought of that.

There are also some spigots dispensing drinking water throughout the train, but on this journey, most of them didn't work. Even the ones that worked dispensed water very slowly. I wanted to avoid buying bottled water, so I made do.