Every camera bag I every had sucked as a serious hiking bag, I'm with the guy that suggested a regular backpack, even a cheaper one is going to feel way better after a few miles and carry everything you want, a high end back pack (I use an arcteryx bora 95) is really the way to go. You can start to load pounds up pretty quick, my normal carry camera gear is near 30 lbs, most camera bags and even good back packs are not suited for much more weight than this, forget chest straps and dinky waist belts, serious weight, needs the correct pack.
Once you start adding tripod, two bodies, long lenses, a laptop things get heavy fast. Not to mention food water extra batteries etc etc. You need to carry all this from your hips, not your back, camera bags are not designed to do this, as most of them want to fit as carry on luggage...
I see the word mountain in your post, you need a real backpack mountain hiking with weight is much less fun without the proper gear.
Everything you see in the picture attached fits in the blue bag in the picture, that's everything I need to shoot and live for ten days, that's 100 plus lbs..
I carry the camera bag on the plane, and the other gear goes into the belly, once I am ready to hike, the camera bag goes into the Backpack.