towing thru Big Horn Mountains in Wyoming

We did it with a 2008 GMC Sierra and a 2011 Jayco 26BH a few years back. Our Sierra was equipped with a 5.3, 3.73 rear end, and 4 speed automatic You don't state how yours is equipped.

I error on the side of caution so I took it slower both up and down. I saw transmission temps of 220-240F as those slower speeds don't allow much air over transmission cooler but dealer said no issues until 270F.

Shortly after that trip we did upgrade to a 2011 Silverado 2500HD 6.0 3.73 and was night and day over the 1500 pulling the 26BH.

Be cautious and diligent in your driving and maneuvers and you should be fine.

UPDATE ON MY POST----my silverado has a 5.3 v-8 with 6 speed tranny---checked to see rear end ratio

We took 14 from Greybull up over Burgess Junction and down towards the Devil's Tower side. We had an F250 V10 towing a 27' Kit Companion, a heavy TT. We took it slow, but on this route and in that direction it was less steep.

You will be fine on either route. Watch your engine and tranny temps, uphill, Use your engine braking downhill.

Been up and down Big Horn with truck and camper in my sig. I would definitely go around next time.

I did it in a truck camper 2 years ago on alternate 14 and that was enough for me. I understand 16 is much more forgiving and I am contemplating doing it in a motorhome this year.

The scenery on 14 alternate is awesome but the grades are----- well lets just say I left my finger prints indented in the steering wheel. I never though I'd sweat any power issues in that pick up with a slide on camper having just finished the Alaska Hiway run in it. I found out otherwise when I started running low on gears to use to get up that grade! I'd do it in a car again but never Alternate 14 with anything that has any load. I may try 16 this year though.

After doing research on this, out of curiosity, 16 is recommended by most reviews I read.

I have gone both routes , we just did 16 in June and that is the only way I would go again.

My only white knuckle experience ever pulling a trailer...... Hwy 16 West to East going down was hair raising and butt puckering. 2001 Ford F150 w/ 4500lb 27' trailer in 1st gear crawling my way down....... never again.

I did 14 east and 16 west and while 16 was probably a bit easier the change of scenery was worth doing both.
Either one is not a huge deal even if you go a bit slow at times.
Your truck is way newer than my old 260hp and 4spd transmission.
Allow yourself extra time and don't make it a race and you will be fine.