If you are in the mountains, the ONLY people that will reliably hear you is the ones you know. [...] In the back country canyons of Idaho, none of these work - cell, ham, satellite phone, cb, mirrors, smoke signals or crying.
Well, that's not quite true.
If you are an amateur operator with HF privileges, you can use a small portable HF rig (like the SG-2020) and a low wire antenna for NVIS propagation on 40m. You WILL be heard in every square meter of territory within (roughly) a 500km radius. Since 40m is a very active band with lots of nets going on, getting hold of someone isn't often a problem.
Yes, it even works from the bottoms of canyons. BTDT.
-=[ Grant ]=-