FWIW, I am a camper and often go to somewhat remote part of mountains. The usual routine once arrive at campsite is set up tent in case of arriving bad weather. Once tent is up, it usually doesn't take long before I check if I have cell reception. If I don't have reception I will walk around a little while looking at cell screen looking for reception. The younger the age the more dependent usually on cell reception. It has been proven there was cell reception in a few areas in their campsite or within a few feet [video=youtube;7zr6r0ozYYY]https://www.youtube.com/watch?v=7zr6r0ozYYY[/video] . I feel quite confident both parents knew reception was there and cell records can probably prove parents had made a call or text or Facebook post while at campsite. Sort of proves that VDK really didn't need to drive to cattle guard for reception if my assumptions are correct.