14A goes through the Bighorns, too.
Last time I was through was 2010 on the way to Redmond, and it was under construction *big time* (as in, I was really glad I was on the GS and have good off-pavement skills...)
16 is also an extremely nice road, with lots of good camping along the way.
You know what I like best of my travels in middle USA? Crossed it dozens of times and its always the folks living there in the plains. They are nice folks, about everywhere and so easy to talk to, very friendly and will go out of their way to make you welcome. Just cannot beat that! I've had "more than once", been invited home to take shelter from storms that were VERY intimidating and dangerous. Complete strangers and just plain good people. I always enjoy the travels in the plains and so many complain about it. They just are not looking or hearing well!....Randy
'07 R1200GS for solo rides
'10 R1200GSA with Hannigan dual sport sidecar for rides with Barley
For the Second Redmond rally I took US 20 from Omaha all the way west. The Pine Ridge in northern Nebraska is really quite scenic as are the sand hills. Wyoming, Idaho and Utah were nice on 20 also.
I'm looking hard at US 26 for most of the route. It seems to pass through some WILD geology along the way.
I live just off US 36 in Ohio and just south of US 30. Both are interesting roads I have used to go west.
US 30 is a more mixed bag. You get into city traffic as you go south of Chicago.
Give thought to US 12 past Minneapolis. The section across Idaho is one of the most beautiful roads I have ever been on.
K1200RS, K1200LT, R80RT, R100R, R75/5