The AP assumes that the caravan heads north late in the year, somewhere between late fall and mid-winter. I thought something seemed strange with the description of the Bearleg Lakes region talking about salmon runs and whatnot, and unless the fish of Golarion follow a completely different seasonal cycle then they do on Earth (it seems to happen between May and July for the most part), that can't be happening at the time the caravan is arriving in the area. It should be closer to the middle of winter, when most of the local wildlife is buttoned down in survival mode (unless I completely missed something, always possible).
Anyone else have thoughts on this?
There are actually a few varying descriptions of places that allow for you to adjust the encounters to the appropriate seasons for your parties travel.
Some of the 'low-land' encounters prior to the High ice give various alternate encounters depending on the current seasonal climate during your crossing. The assumption is for an 'off season crossing', but you aren't going to be shackled to that if your players don't want to take a particularly dangerous crossing or for some reason your game did not begin at the exact time the AP planned. The extra info is there so you have some alternatives to adjust for a non-winter crossing.
The Bearleg region I think also mentions something about ice fishing as well if you are gathering supplies during the winter months. I don't have the book in front of me at the moment.