Where I'm building a new house is line-of-sight to the U. Plateau. An experienced pal has told me that there are some canyons therein so deep that you wind up with marginal/no GPS Sat signals that cannot be relied upon to get you home. Them's some deep canyons.

Irrespective of that, I'm wondering about this... I just drove up a back road toward the Grand Mesa, and dry-to-wet-to-slime-to-snow roads developed quickly - within 2 miles - but developed in a "linear" way. I.e., I knew it was getting worse, so me and a buddy backed out and down in my Sport. Plus, we listen religiously, on FM radio rebroadcasts, to the NOAA weather/avalanche forecasts from Montrose CO.

Encountering 4' of snow doesn't happen typically at the drop of a hat. With all due respect, did your pal just keep plowing ahead, ignoring the obvious signs [roadside snow buildup/snow on vegetation] that he was driving into an irreversible situation???

We just had avalanche death #3 this season here in CO. Snow/slab buildup on sloped surfaces w/wind can be thought of as the same type of buildup that your pal encountered on what I assume were more level surfaces. In either case, knowledge [about conditions] is power...

Toting Survival gear makes sense. Not KNOWINGLY getting into situations where that gear has to be deployed also makes sense.

What's the whole story? As with everyone, I'm glad - along with CO Search and Rescue - that the story had a happy ending...