So you find yourself completely lost, or injured, and you can't make it back to the trailhead. You have no service; you turn off your cellphone and don't know what to do with yourself. But wait....have you made a mistake?
Your Cellphone Can Save You
According to this post on backpacker.com, keeping your cell phone on, or at least trying to call 911 even if it doesn't connect, can help rescuers find you should you not get back when you were supposed to!
1. Your phone sends out some electronic packets to the nearest towers; even if there isn't enough signal to connect a call, the tower may receive traces of your phone and your location.
2. Depending on who your service provider is, you may find that they receive a packet of information when you turn your phone on, and thus can have an idea of where you are. When someone goes missing, law enforcement officials can find out that person’s cell phone number, call the service provider’s special emergency hotline, and access the data trail for a specific phone.
And so, what should you do?
Because Search and Rescue teams might not know about these technology possibilities, you should tell your family member who you leave your emergency contact info with about these things. Then, if you become dangerously lost or injured, dial 911 even if you don’t have strong service. For better service, head for higher ground—cell phones operate by line-of-sight radio waves.