4x4 roll over and recovery

Second vote for the In Reach Explorer, in either flavor. We used them at work. Also the same sat system for remote oil and gas well data. You might have to wait, but at least once a day you will get a direct overhead pass and your message will get out. Deep,steep hollers, trees, whatever. Walk or crawl 100 yards to an open area, and she will probably latch up in less than 10 minutes. Not perfect, but the best. There is also the Spot, EPRIB (PLB), Sat phones, and other stuff I don't know about. Think of these gadgets as your ace in the hole, boot knife or that .32 down in your shorts.

Still the In Reach is my favorite, because of the 2 way texting, at a cheap price, in a small easy to carry package.