I thought I had posted to this thread but apparently not...
Anyway, I would basically echo what everyone has said. With the addition that I found my hamstrings to be my weak link, especially in uphill hiking. Since I've started hammering them more specifically, I've improved both my strength and mountain-shape.
Interesting that you say that. I was part of a brutally difficult elk hunt and pack out this Fall -lost 15+ lbs and came back very weak (Backsquat dropped by over 40 pounds) . My whole body was pretty wrecked, but both my partner and I commented how, surprisingly, our hamstrings were the only major lower body muscle group that didn't hurt. Hips, Glutes, quads, calves, ankles and feet were all lit up and severely depleted, but hamstrings? Nothing. Seemed odd considering that muscle group should take a lot of strain with heavy weight on the back while maneuvering steep terrain.
On the subject of overall training, I do agree that it is possible to train strength and endurance simultaneously with careful consideration for volume, but, given that our pursuit of hunting is seasonal, it still makes sense to break the training cycles into periodic areas of focus. So your endurance is down? It's January. Do you need endurance right now? Once you have a solid base level of consistent training, which, It appears that everyone contributing to this thread so far does, endurance should return, increase and respond rather quickly to training, especially if you have a solid strength foundation in place. Strength, while it may not "get you up the mountain", is the most versatile and malleable component of overall fitness.
I also think that these discussions, at some point, tend to split into 2 camps: those whose goal is to be in shape for hunting and hunting only, with all other aspects of fitness being frivolous. The 2nd camp being those who want to be in shape for hunting as well as be all around "good" general athletes. One is a means to an end and the other is more process oriented. If you fall into the 2nd camp, you would likely train hard even if you had nothing to train for, you just enjoy training and geeking out on every detail. If you're in the first camp, you mainly don't want anything to inhibit your hunting, so you do what you have to do to be ready. Nothing wrong with either approach, but I think that is where these training philosophies tend to most often derail from discussion into arguments. One camp doesn't see the point in hauling a set of shoulders up the mountain, the other camp figures if you're going to work hard, might as well have a set of strong shoulders.