I disagree with #1, I live in Colorado and many trails here are out of cell range. My advice here is either get a satellite phone and/or do some research about

I disagree with #1, I live in Colorado and many trails here are out of cell range. My advice here is either get a satellite phone and/or do some research about where you are going and only go if it's a well travelled trail. I often go out by myself into places without cell coverage but I always research the place to make sure that if I run into issues, there will almost certainly be someone there to help me. It's not a perfect system but it's better than going in blind somewhere. Also, pack 2-3x the water you think you will need.