How did the pioneers and mountainmen make it without a cell phone? I'll just never know.
I've got reception on the peaks around Afton. I got it in more places than I thought I would too.
If I loose reseption I don't worry too much though.
"My sickle has a boattail"
"hidden soles leave .308 holes"
If you're going solo a sat phone isn't a bad idea. If you're going with someone then a cell phone will work in most of the areas I've been in g and h.
The SPOT gps messanger is a whole lot less than going the sat phone route too. You'll be able to find cell service-it may take some hiking but you'll find it.
It is worth taking a cell phone. I have been suprised at some of the areas that you can get coverage in the Salt River Range. +1 on Deerlove. If you can see Star Valley you will usually have coverage.