At least twice a year since moving to ID and going back to Moab to camp and visit with friends. And when living in Moab, every time I went north to ID/MT/WY it was via Highway 6.
From Provo some curves and you climb to Soldiers Summit, which is only 7400 feet, but in spring/fall you can have some nasty weather up there. In my spring and fall trips I have encountered everything from hail to snow to blinding thunderstorms. (Just a note: Hwy 6 between Spanish Fork and Price is one of Utah's most dangerous roads, primarily in the curves before Spanish Fork. I have travelled it many times, and have never even seen an accident, but it is one of those roads that needs respect. Just take your time and all will be ok. So you will see quite a few white cars with a Beehive on the side, with and without lights on top.
The Deadliest Roads Are Rural : NPR
After the Summit you drop down into Helper and some decent curves before you get there; usually slows down at that point. From Helper into Price easy drive BUT SLOW DOWN when you hit Wellington; just south of Price. Last time I went through there the state and county were doing a crackdown on the speeders through town.
(Last year there was some construction on NB Hwy 6. The State was adding another lane for northbound, I believe it is finished now. It was needed.
If you need fuel; there are plenty at the Price exit, but a pain in the butt to access (IMHO), but there are two easily accessible stations in the southern part of Wellington. A shell on the west side, and a Chevron further down the road on the east side. The shell's pumps are parallel to the highway so easy access for a trailer (something I like even with a popup)
; the Chevron they are perpendicular to the hwy.
After price it is a LONE straight drive to I-70. But it can be dangerous too many people passing in both directions even when everyone is doing the 65 speed limit. However, they have been adding more passing areas. (A state trooper told me that they keep requesting more passing zones to keep down on the accidents; both south and north of Price).