One strength of Amateur Radio (aka. Ham Radio) is how flexible the hobby is. One type of operation that is very interesting for folks that like to Overland or Backpack is called APRS (Amateur Packet Reporting System). This is a mechanism by which radio operators can share digital information such as the raw NEMA2 position data from a GPS and transmit it between radio devices. With advancements in radio technology, we now have the ability to easily use APRS completely contained inside a handheld transceiver. To highlight how this might be useful, we're going to describe two different scenarios.
The Rimrocker Trail
In 2016, I planned on attending an off-roading event in Moab, Utah, called "Rock Therapy." I'd start in Colorado, as I did some work there the week before my vacation. I decided to make an overland trip with several Colorado natives called the Rimrocker Trail, which started in Montrose, CO, and finished in Moab, UT. This was roughly 170 miles of trails with less than four miles of pavement, right through the heart of the Rocky Mountains. Because of infrastructure ham radio operators have put in place, my wife, who was at home in Texas, was able to keep an eye on my progress, figuring if my truck didn't move for more than 24h, she might call for help on my behalf.
She was able to track me because APRS information from an amateur radio station gets repeated, in most cases, onto the internet and is viewable from sites such as APRS.FI. Ultimately we stopped to camp overnight but otherwise had a safe drive down the trail and made it to Moab with no problems.
Big Bend National Park
In my second scenario, another Ham Radio operator and I go to Big Bend National Park. I decide to drive Black Gap Road and tell my friend that I'll be back at camp by 3 pm. He decides to go fishing in the Rio Grande. When he gets back to camp at 3:15, and I'm not there, he tries to call me on the radio but finds I'm out of range. When 4 pm comes around, and I'm still not at camp, my friend sets out toward Black Gap Road, turning on his APRS transceiver on the way. About two miles down the road, his receiver hears a transmission from my truck with a bearing in line with the road and a distance of about 5 miles. My friend calls for me over the radio and is now within range. As it turns out, I got a flat tire and was on the trail changing it, which was why I didn't make it back to camp at my scheduled time. APRS was able to clue him in to where I was, and had I not answered, it would have led him to my location.
Conclusion
APRS is simply another tool a licensed radio operator can use to bring additional levels of safety to the wilderness. Like all tools though, there's a skill level that only comes with proper preparation and training. Knowing how to communicate your intentions clearly, and properly use and configure your gear can add a safety layer in the wilderness.
In both scenarios, because we had clearly communicated our intentions before setting out, APRS became a useful tool in locating our whereabouts.