The other issue to consider here in Colorado is the wind.
Our first TV was a 2013 F150 w/ the EcoBoost engine. Our camper is a 2014 Raptor 27FS, factory weight of 6885 (it's a bumper pull toy hauler). Power to tow was not a problem, but sway/wind certainly was. We added airbags, and better rated tires, drove slow, etc etc. The truck was just too small and the trailer would push it around quite a bit.... and that was without a toy in the garage area.
We gave up and never even bothered to take it in the mountains until we got a bigger truck, since there, on top of the wind, you have the grades to worry about.