The Beartooth Pass, WY/MT
In 2009 I did a 7,000 mile solo trip across the US then back through Canada. I saw a lot of amazing places but none as amazing as the Beartooth Pass, RT 212. Fantastic twisty ride of about 63 miles. While in Colorado my sister told me I had to see the Garden of the Gods in Colorado Springs. IMHO if that is the Garden of the Gods then the Beartooth Pass is their playground.
I rode the pass West to East from Yellowstone in July. At the pass, 11,500, it was just slightly above freezing so dress appropriately and don't miss it if you get the chance.
If anyone is interested there are photos and videos of the trip at