I live and tow in Colorado all the time.
I think most of the new trucks should be OK towing 19000 lbs up the Rockies, as long as you are happy with 45-55 mph.
I tow with a 2011 chevy, sometimes about 17000 lbs. I can maintain between 45-55, depending which grade you are talking about.
The bigger issue is going downhill, especially going east, since the grade is curvy, long and steep. Plus, it is only 2 lane, and there are many semi's maintaing between 55-60. Without a good exhaust brake, you might burn your brakes out. Even with my EB on, I have to touch the brakes now and than, but not too much, just now and than.
Most reviewers have said the Dodge and GM exhaust brake perform better. But maybe the Ford EB is good enough, I don't know.
