Heads up, but if you can find some Nextel iDEN cellphones, they can actually work off network with one another at ranges of up to 6 miles. I'd plan on that being considerably less in the mountains, but still plenty to cover most resorts and backcountry tours. Seeing that the iDEN network is no longer as of a couple of months ago, you should be able to find them dirt cheap as they're essentially worthless.
"People say that marijuana smoking is going to get in the way of my career. I say to them that on the contrary, my fighting career is getting in the way of my marijuana smoking." -Nick Diaz