Some folks take big rigs over Red Mountain Pass (US 550). We do not and will not take our bus over this route.
Monday we were coming back from jeeping in the San Juans when we were meeting a out of state car that was driving in the middle of the road. There is alot of this road that is narrow with a 500 to 1000 foot drop off and no guard rails. We had to come to a complete stop to aviod a head on. Many of the curves are so short it is interesting to watch the few semis that drive it. Some of the curves are so tight the trailer will cross the center line even when the steer wheels are in the dirt.
The safe option is to go towards Cortez and take CO Route 145 over Lizard Head Pass. The grades are not a steep as Red Mountain and no short curves. Adds some miles to the trip but worth it to us. Some may say I drove Red Mountain. We think you are nuts.