I've been with AT&T, Verizon, and T-Mobile in the pacific northwest (Washington, Oregon mostly) for the last several years. During that time I have traveled both to the more metropolitan western Oregon and Washington, as well as the more rural eastern sides of the states. AT&T is pretty good around major metros and most semi-rural areas. T-mobile is very spotty outside of the metros and most major interstates, and many rural areas of eastern Washington and Oregon they have zero coverage at all. I've never used Sprint in this area but I don't know anyone who even has Sprint so that should tell you something. Verizon seems to have the best overall coverage in the pacific northwest, especially the more rural areas. Even when really out in the middle of nowhere they always seem to have some coverage to at least get a call out if nothing else. I can't speak for Idaho as I have not traveled in that area in several years. All of the major companies are awful in terms of pricing and customer service when you have a problem, but the best of all of the evils seems to be Verizon in my experience in this region of the US.