Actually if you want a nice scenic drive go 15 to 93 and all the way up to the Can-Am border.
The interchange will be in Blackfoot Idaho just south of Idaho Falls. You go through towns but it is a pretty decent speed road. Only thing I would worry about is that it is a known running corridor (don't ask) so when you start getting near towns and through them you watch your speed, they don't fuck around at all.