Good reminders, Glenn! I'm glad there were no repercussions! It's good that you were in an area with cell phone coverage (not usually true out here).

Another thing; each participant should be instructed to tell the group leader if (s)he has to leave the main group for any reason, even for a few minutes.

We had a very recent tragedy here in the Mt. Hood area in which a pair of hikers split up about a mile before the end of the Timberline Trail because one of them had a sore knee and wanted to rest a while. His body was found some days later. He had taken a wrong turn and evidently was hypothermic. I suspect he may have already been a bit hypothermic when he left the rest stop because when he hit the criss-crossing trails in the ski area, he went up instead of down, and climbed a couple thousand feet. I'm sure the guy who went ahead will blame himself for the rest of his life, but, as a lesson for the rest of us, if your buddy is not feeling well, stay with him/her. If you have to leave to get help (not true in this case), make sure the ill person is well protected from the weather (since this was a backpacking trip, it would have been easy to set up his tent and get him into his sleeping bag). While normally the ski lodge (the goal) would have been clearly visible from the stopping place, I understand that the clouds had rolled in.