There are some pretty good climbs/descents between Salt Lake City and Vegas. 5 or 6 in Utah, The Virgin River Gorge in the Arizona strip between St. George and Mesquite, and then several again in Nevada into Vegas. The Virgin River Gorge is quite intimidating and not for the faint of heart (although if you take it very easy and concentrate on the road, not the scenery, you will be fine). Also do the gorge in daylight, although night time is not nearly as busy, it is more difficult at night. If you need more info on this route, let me know, before I retired I was a truck driver on that route for 20yrs.