We backpacked the Bob Marshall Wilderness pretty extensively when I was a kid, with our various GSD's. At the time the grizzly bear population wasn't what it is now and we didn't worry about bears too much since we were very careful with how we handled food etc.
--booties, definitely if you're going to be on shale, schist or granite rock. The rock slides mean rough walking and in most cases dogs put on at least twice the miles we do (at least ours did because they went from the front of the strung out line of family members to the back and then back the front, making sure we were all there). The first time we went my dad's GSD ended up with raw feet and a few of us sacrificed our around the camp shoes (moccasins) to cut them up for booties for her--she didn't much like them at first, but did eventually.
--good recall is imperative. Between squirrels, bears, and all the other animals, the smells, sights and sounds can be pretty exciting for them. My current GSD would NOT be turned loose like we did with ours when I was a kid.
And I would ditto the previous poster too! First aid, a pannier/pack for your dog to carry his/her food and gear, extra food for all that calorie burning etc.
Chris, mom to:
Tank (Cardigan Welsh Corgi)
Valentine-our ragdoll cat
Two great skin kids