Where I am right now (mountainous region in Northeastern Oregon) it is not uncommon to have zero cellphone reception. Since anything can happen from Snakebites to landslides to bad falls or just bad luck, I dislike the idea of being out of contact since most of the time, I'll be prospecting alone.
I discussed it with my brother in law and he sent me these two links:
It appears to be an affordable and practical solution to the problem. A lot less expensive than a satellite phone!