I am a bit iffy with electronics, they just never seem to work.
Kind of like with Izzy's answer. Give them a try and hope a signal gets noticed, but try other things too.

Ontario Hydro Northern used to tell their line crews that if they got lost or stranded they should burn a tree up.

The idea is that if they can find a dead spruce off by itself, maybe on an island or in the middle of a rock field, hopefully near the top of a hill, then it would make a big enough torch for the firewatchers in the fire towers to see.
The fire watchers will note it and send somebody to check it out like they do with all fires and then let Hydro know that they had found their crew for them.

A fire shows up a long way away at night, but even in daylight
smoke can be missed in the north because it looks too much like fog or mist patches.
Also small smoky fires don't make a strong enough heat column to punch through the temperature inversion layer that covers northern forests in the cold weather.
The smoke tends to just hang at about the top of the trees, just like the ground mist.

If they are looking for a lost person any sign of activity will be investigated.
So they would prefer one big fire instead of three small ones once they have started searching.


I liked the answer about burning down the telephone pole too.
Kind of like "If you break it they will come!"