So I know it's a long way off but we are planning a grand trip out west (from Boston) to camp and do outdoorsy stuff in National Parks next summer. Our time frame is two weeks. Our boys LOVE trains. My thought was to take a train cross country at least one way (they have super cool family sleeper cars) rent an RV (still trying to decide if we would want to rent a car to haul too) and do camping for 8-10 days, then come back. Probably fly one way. I have played with several different scenarios. Maybe the train (3 ish days) will be too long with a 4.5 year old and a 2 year old? Should we fly to Chicago, train from there (only 2 days) and then fly home? Should we fly both ways because a train trip will drive me nuts? Should we rent an RV here and use it for the whole trip and eliminate the train?
Oh and money is not a factor.
Also, which parks are a must? We've done Glacier extensively and I think it's too far north for us right now, but I'd love to get a loop of a few others a little more south.
Any thoughts on the matter welcomed, I just love daydreaming planning this!

Re: Travel planning advice
Please tell me if we do a train though I don't have to do carseats on the train!
I think it's either no train or at least one overnight. The fun part for G would be sleeping on a train. Ok, well the fun part for me too.
I have wanted to see more of Denver myself (only drove through) so that's definitely a possibility! Don't you guys have a good zoo?
I am having way too much fun coming up with these plans.
Fly to LA, go to Joshua tree park (DH wants to go. I know nothing about it. Except U2 album), drive to Prescott (another DH pick, said he heard it was cool), Santa Fe, drive through what looks like a bunch of forests in southwest CO (any recs there appreciated!) Moab, arches, canyon lands, Grand Canyon, then fly out of Vegas. We have two solid weeks so we are leaving some time flexibility in the route as we may want to see other things along the way and spend more time somewhere.
I really want to do Yellowstone but I don't think I could contain my wanting to do longer hikes. The "not too much hiking" factor is obviously an issue in planning so that is why there is a little more urban fun in this route with Santa Fe, LA and Vegas.
And we're shooting for last two weeks of May. Woo hoo!
Also when discussing this with DH I kept pointing to my phone and saying, "well she said..." To DH. I'm not sure I ever exactly told him about the bump so now he must think I'm having some "Her" type relationship with Siri.
Also I am totally getting one of those uber babysitters for the day so I can do this without the kids. I'm thinking wearing Arlo in the ergo going down a rock water slide wouldn't be the safest.