Why are so many people telling him to buy a 3/4 ton? He already said he bought a 1/2 ton and is asking for advice about towing with that truck!
Also, the gross weight of the trailer is 7,789 pounds, not 10,800 as the first reply stated, nor 8,800, as the next reply tried to claim.
The gross 7,789 pounds might be a bit much for that truck in Colorado, but let's say they load 1,000 pounds of gear, which is what I constantly read on these forums is the "average" amount for a travel trailer.
That puts the trailer at 7,089 pounds. While that is the most I would want to tow with that truck at those grades, I think it is definitely doable.