As a flatlander (Nebraska) my whole life I too worried about mountain driving. Just follow the advice on this thread and you'll be fine. Up is easy just keep it slow and let the tranny find the gear. going down keep it slow and use lower gear, in most cased just turning off the overdrive will do it. set a speed you don't want to exceed, in my case it was 40 - 45. then when you get to that speed brake hard to about 25 - 30 and repeat. I have now driven I80 and I70 both directions at least 4 times from Omaha to west coast in a gasser and enjoy doing it.