I just read a story from the western Montana newspaper "Missoulian". It tells of a young couple from Wisconsin who were headed home on October 28 following a visit to Yellowstone NP. They'd booked a motel in Miles City, MT for their first night homeward bound, punched its address into their smartphone GPS, and followed its directions to Cooke City, MT and US 212--the Beartooth Highway.
Problem was the Beartooth Highway had been closed for a month and they said nothing emanating from the smartphone indicated US 212 is a seasonal highway. They also indicated they'd seen no signs indicative of its closed status.
So, they got to a point about 35 miles from Cooke City, encountered deeper and deeper snow, decided to turn around, and got stuck. They rationed the little bit of food they had with them and slept covered up by the clothing from their luggage. After 7 nights marooned, some of them with subzero temps, a local rancher, having heard news reports of a couple missing since last seen in Yellowstone NP, took it upon himself to take his snowmobile out the Beartooth Highway to see if he might find them.
The rancher did find them, immediately, and brought them out on his snowmobile. The couple had given up hope for rescue and had written goodbye notes to their families.
Why anybody ventures out so completely unprepared, and with zero in the way of situational awareness, is beyond me. Trust my life to a "smart" cellphone? No way.