Will be camping in Idaho Falls before heading to Yellowstone N.P. How is the drive on route 20 over Targhee Pass into W. Yellowstone? We're pulling a 30' 5er with my 2015 GMC 2500 4X4 (gas).
You will not have any trouble wth Targee Pass. The only time it can be any trouble is in the winter, mostly from blowing snow in the open area on the Idaho side. The climb from Ashton ID to Island Park ID will be more of a challenge but it is mostly straight.