I just got back from a 3 night family trip to Ralph Bice lake. It was myself, wife, and 3 kids (6, 4, and almost 2) in an 18.5' Quetico, along with 5 packs. We were very organized, pull up to the portage, unload kids and bags, pile the lifejackets, paddles, and MEC Slog off to the side and go over the portage carrying the other packs and canoe. I'd start heading back to get all the remaining stuff and we would very efficiently get back on the water. We were heading out on Saturday and as expected the portages were busy but everything went well, we got back to the access, pulled the car up and loaded stuff in however now there was only 4 life jackets.

I searched all around the access point and my lifejacket was nowhere to be found. I thought I may have left it behind at the last portage but no, my wife remembers handing it to me and I remember trying to fish it out from the pile. I don't remember putting it down at the access but I assume I would have put it beside my MEC Slog. So we concluded that either someone accidently packed it into their car and drove away or one of the groups going out took it into the backcountry. 

Losing the lifejacket is not a big deal because it was a cheap Body Glove model from Costco. Also, The pocket had my Burton TruArc3 compass. I don't really want to replace either of these items but I guess I can look for sales on premium lifejackets in the off season. This has never happened to me before but when I think about it I wouldn't be surprised if this happens all the time at any busy portage or access point.