Unlikely, they have a very limited range and unless searchers knew that he had one, they would have no reason to be monitoring those frequencies. But certainly better than nothing.

You would be much better off getting your amateur radio license and carry a 5 watt dual-bander HT (walkie talkie) along with ARRL's shirt pocket repeater directory. That would give you a chance of hitting one of numerous amature radio repeaters out in the back country and a ham is more likely to be monitoring one of those frequencies.

Craig.