回复：带了孩子就更要慢行了。我刚走过底特律经盐湖城到Zion一段，一

Thank you!

I had a chance visiting Zion, Bryce & Grand Canyon 15+ years ago. In a lot of area, it goes 30 - 40mph. I am using 40mph average now to calculate the non-highway driving time. To be honest, I am betting the day time is longer in June (dark after 8pm?) which allows some offset to the difficulty.

But I may very well under-estimate the coming challenge.

One of the alternative for me is to go Yellowstone & Glacier which seems more manageable (weather friendly too). But tieing Glacier with Calgary, Vacouver & Seattle appears more reasonable. That's one block for me to cover in the future (flying will be required).

Another block is to associate NM, AZ & lower CA together during the winter time.

Thank you for the advise! All the advise indicate that my plan is an over-stretch. I will either have to make it more manageable or go for alternative.