Shannon Vore and her friend C.J. Bouchard were out four-wheeling in their Jeep last fall when a passing trucker warned them of what looked like an ATV accident nearby. They said they’d investigate. Deep in the Rocky Mountains of northwest Idaho, there were no towns nearby and no cell phone service.

But both Vore and Bouchard were newly licensed amateur radio operators, also known as “hams.” In amateur radio lingo, the operators are “hams,” and they transmit on “ham radio,” a spectrum of noncommercial radio frequencies. Vore and Bouchard found the accident site and two critically injured teenage girls. After establishing contact with another ham on the national calling frequency, 146.420 MHz, Bouchard handed off the microphone to Vore and began some basic medical treatment. He stopped one of the girls’ bleeding with a tourniquet.