Flying out of Marfa Texas, about 5 years ago a couple of us landed out
- and I do mean out. I had to hike a few miles past several jack
rabbits, and many spiders and snakes to the only ranch house on
200,000 acres.
We were having little luck with cell phones so I tried to get an
airliner to relay. I called on 121.5 multiple times. We were just in
such a remote area I got no response.
Luckily we did not have an emergency because we had no luck with the
airliner relay.

I'd try the scan function on my handheld radio next time as that is a
good suggestion.
How else would you know what frequency to try to call on?

I figured that a 5w handheld radio would have a pretty good range to
reach airliners at cruising height.

Chris