In areas with lots of people, It can work. Around Lake Tahoe where there are dozens and dozens of ski runs and golf courses, many carry the radios for communication with family and friends. As such, several lost people have been rescued by SAR using the radios. Either the SAR radios pick up the transmission or another recreationalist does and calls in to the Sheriff.

I have noticed while hunting in remote places, there is usually at least one other group on the radio in each area, but need for line of sight to communicate clearly is very limiting in mountainous places. I can hear them, but they can't hear me.

If SAR knows you have a radio, they will monitor for it. Otherwise, it would be a roll of the dice.