I've done a couple of fly-in trips in AK, in the Lake Clark/Iliamna area. They dropped us off on a lake (float planes). Both trips were for Caribou.

In those cases they set you down a few days in front of the herds, and hope that you are in line with them. When they set us down half a days walk from the main traveling lanes, it was a brutal time. We had to walk 4-6 hours in the dark to get to them. It was even worse when you got one. So if you are going to be in that situation bring a spike-camp set up in addition to your main camp set up. It will let you stay overnight in the zone.

Bug nets, lots of quality socks, extra camera batteries, the usual.