yr2017 wrote:
If you don't already own a trailer, consider a fly/drive - fly to Denver and rent a class C there
Very good advice and not just because of the distance. If you have not had an RV before, it will give you a chance to find out if your family really enjoys being together in a "confined space" (ie., RV) for that long. That is an often overlooked, but very important, part of making an RV buying decision.
Cruise America has a big rental facility in the Denver suburb of Federal Heights. It is a convenient distance from DIA and on the north side of town. So you wouldn't have to learn to drive the RV through downtown Denver's horrible I-25 traffic to be on your way to YNP. The Denver Lazy Days RV dealership is even closer to DIA and also rents motorhomes.
An alternative, if you have a truck or SUV with a hitch, would be to drive to Denver in two very long days and rent a trailer. Colorado Camper Rental's website can be found
HERE.Incidentally, it takes 12 travel hours to tow my fifth wheel from my house in a Denver suburb to West Yellowstone, MT. And, in summer-early fall, the trip from Cody, WY, to West Yellowstone takes the last two hours of those 12!