Alright. I am also a photographer, although I have not moved on to really climbing through the wilderness yet. I'd love to do it, but have not yet. I currently carry a Bersa Thunder380 which is small and lightweight. But I don't trust the gun enough to carry it with a round chambered and to carry it anywhere other than my ankle. So this is not a good option.
I want everyone to take note that this is sort of out of character for me. LOL! I am going to reccomend a Glock.
While I am a complete Sig fanatic, I wouldn't take my Sig out into the woods. It isn't that I don't think it could handle the job, but being a metal gun it is slightly heavier (and I assume, if you are like me, you don't need any more weight with a camera bag in tow while wandering on uneven ground) and is prone to surface rust. The Sig Pro, which is a polymer gun, is a good choice to combat that issue, but I have very little experience with them and therefore I cannot reccomend them and feel good about it.
The Glock is polymer, light weight, and you can get a decent caliber in a smaller size. And you can pretty much torture the every living daylights out of one and it will still be good to you. So if you are a camper, you don't really need to worry too much about the rust issue, although it does still have metal parts you'll need to look after. It will gladly hold up against just about anything you toss its way, such as bumping into trees, falling into mud, etc.
So I say rent a Glock at the local firing range. Research various calibers and see what size Glock you can get in it, then go nuts on the gun rental (if gun rental is an option at your local range). If you like it and buy one, I seriously doubt you will regret your choice.