Zepher to CA from Den or Yellowstone
 

Help..... wanted to take a first driving vac from IA to Yellowstone traveling thru South Dakoda with sites on the way. Or then got the idea to drive to Denver and board the Train Zepher for site seeing all the way to San Francisco. Any opinions or suggestions?

I am not a fan of long distance traveling by train. It can get very boring very quickly since stops are few and far between. Going to the dining car for a meal or a coffee is not the same as stopping at some local coffee shop when driving--the latter is more of a break and tends to be more interesting. I would stick to the original plan of driving to Yellowstone and back.

There are some nice views from the train . . . But there are similar and sometimes better views from the road, and you have the opportunity to stop and linger places if you want.

The California Zephyr is a nice train route but for sight seeing you should consider driving instead.

It makes a big difference with what month, how many people and what type of scenery you want to see.
You could get on the Zephyr in Iowa (or Omaha) and take it to Denver and rent a car there to see Rocky Mt and maybe Yellowstone and Grand Teton.
Nebraska and Kansas are among my least favorite states to drive across.

Thanks for the feedback. Yellowstone is a little overwhelming. So big. How long will it take to see the top 10 must sees??

Normally, I'm a big fan of cross-country train travel. In this case, however, the closest you can get to Yellowstone by train is Salt Lake City and, if it's on-time, you'll get there about midnight.

You are right it can take a fair amount of time to see YNP. I've been there for a couple of days and I've been there for ten days and neither was long enough for me, especially if you want to add in Grand Teton NP and the surrounding area.

In your OP, you did not say when you are going. late spring, summer, and early fall should have all the roads open but, depending on when the snow starts or ends, other times may require access by some kid of now machine for much of the park(s).