Dave :
Lots of good advice on gear already presented here. I'll add some (perhaps lengthy) thoughts...
Firstly, if you're looking at packs, look for a pack you like the fit of first and fit the camera gear second. Unless the intent is to carry the maximum of camera equipment, work with the priority issue first - camping and hiking gear. IMO, most camera packs are dandy for camera gear, and (mostly) pathetic for backcountry packing.
The store you look in should have weights that you can load a test pack with. If the store can't accommodate this, tell them to pound sand between the paving stones in front of their store, and buy the pack elsewhere :twisted: . Spend as much time as you need to pick a pack that works well - it's a substantial investment but directly pays off in less pain.
Spend the money on a pack that fits you well. I can say with bitter experience that every pack I "saved money" on was ultimately wasted money. Packs are a lot of like camera gear - you'll get results from lesser quality equipment but you have to work harder at it. That essentially means chafing, blisters, and big-time pain with a backpack for serious time out there.
You can pad the camera gear with materials you're bringing, or use some lightweight protection to avoid the gear getting dinged in the pack, depending on your specific needs.
....
Look at walking sticks, and not those great hulking things you can use for a quarterstaff (unless you're joining the Merry Men with Robin or practicing for a pugil stick competition). Instead, look at Leki walking or trekking sticks. I was a real hardass for years about these, deriding people who used them as sissies, but then I have to say... I was completely wrong. Walking sticks are a major aid for long treks. Now, a bit older, greyer etc., I wish I'd had them in New Zealand on the South Island years back - they'd have made it a lot easier.
They're handy for fending off brush, supporting you on an uneven slope, keeping mountain lions at bay, etc. O.K., O.K., I haven't had to fend off a cougar recently, but the concept's there.
Highly highly recommended, even if the learning curve for their use isn't instantaneous.
....
You don't mention if you're going solo or not. I hike a great deal of the time solo whether it's back to and from remote slot canyons in Escalante or on snowshoes in the backcountry of the Sangre de Christos, so I can make a few cogent remarks about this.
Plan to be stuck by yourself for a least a night or maybe longer. For where you're going, that means gear to get through a night of thunderstorms, maybe temps of 40F or less, fire-making equipment (regardless of fire advisories - making a fire may mean life or death for you), a good real knife (not just a Swiss twenty part thingee - sometimes a long blade is better), a pocket chainsaw (Google it for a place to buy near you), a Space blanket, some glowsticks, and thermal handwarmers.
You've already had the advice about cellphones, GPS, and all that jazz. Here's a low tech device that's saved more people than all of that gear combined - an old fashioned athletic whistle. It's piercing, carries for a fair distance, almost never has "dead zones" <g>, and can guide rescuers to you when the batteries on all that fancy gear are long dead. Doesn't weigh in too heavily either.
And most places I've gone are dead, dead, dead, for cellphones anyway. That lad in Utah probably wouldn't have had reception where he was. I was in the backcountry of Escalante about two weeks later, and BLM folks didn't much like anyone going solo then, but with care, a person can reduce their risk a bit. A cellphone might just help in this, but being aware of the surroundings is a lot better IMO.
As a friend who's a writer comments, "You have to pay intention to everything around you."
....
Raingear's a pretty essential item for the Appalachian trail. Pick whatever you want to carry - all the neato technical gear is pretty good for light rains, but if it's a drencher, you'll get wet nonetheless. The old-fashioned rubber-lined stuff's a bit heavy, and doesn't breathe at all, so it's not recommended. Sounds like you've picked some good clothing already, so you'll dry out O.K.
It's just water, after all.
Having said that, I keep delicate gear (camera, lenses, cellphone) in ziplock or similar generic plastic bags. Over the years, I've taken a spill or two into rivers and streams, and this has sufficed quite nicely, even working very well when I stepped in a pothole in a flooded slot canyon a couple of years back (water over my head, water over my arms extended above my head with the pack, and a couple of feet of water beyond that - a definite real test).
....
Lenses ? Hurm... I'd bring my 12-24mm for those great expanses, moments where the vista is like to stop my heart on the spot, and such times. About any of the good zoom WA lenses would do, of course. I'd likely bring my 70-200mm for the other stuff, and maybe a TC. I have an ultra light Gitzo (1027) that people laugh at for tripod work, but I can bring it almost anywhere because it's small and light. Takes some care to arrange as I'd like, but it works passably well, and it's damn' light. I don't bring a fancy (heavy) head of any kind for serious backcountry hiking/camping.
I'm tempted to bring the 28mm f/1.4 for some night work, but I haven't been doing that so far. I brought my 85mm f/1.4 along once to shoot some crisp images of a friend, but that was another matter, and just a daytrip anyway.
The D70s is a nice idea, and your thinking echoes Thom Hogan's comments in this vein. I'm sticking with my D100 for the moment, but the D70s is a bit of a temptation, I'll freely admit.
....
If you're fifty, you're a nominal adult by age (we haven't met, so I make no judgments about you - others can comment on me), so I'll broach an adult topic or three on health.
Bring toilet paper. Amazing how many people can't figure this one out, but there it is, and not too pretty with the ones who can't think this through. Bring plastic bags to truck it out if you're in a "no waste" zone. People forget that too. Bring twist ties to close up the bags. That one gets obvious rather quickly.
Bring Tucks swabs in individual foil wrappers or some like generic from the drugstore for those times when you have distress at the lower end. There are various alternatives in this arena - pick which one you like best. Four to six will usually suffice for most "bad times". Nineteen times out of twenty on camping you won't need these, but that twentieth time makes up for carrying them all the others !
Bring antibiotic creme, typically a "triple-antibiotic" mixture for bites, cuts, scratches, etc. Don't get any of those one application tubes - bring one of a few ounces in size. You may need to make multiple large area applications for cases of abrasions (e.g., slip'n'slide on a gravel slope).
Bring ASA/aspirin or ibuprofin/Advil. Amazing to me just how much this helps on a cold damp morning when yesterday's hiking sets in as stiffness, or when the arthitis in my hands is keeping me from holding things. Kinda handy, too, if you've taken a spill and are bruising, and can even help a bit (ASA) for sunburn.
Others have mentioned bandaids - I also bring elastic bandages and a couple of sterile gauze panels. The elastic bandages are the newer "self-sticking" kind that you don't need those nasty metal clips to keep in place. I've used the elastic bandages several times after spills, and used the gauze and bandages on someone else I met who'd gotten pretty hacked up (long story).
I'm assuming that you've already learned about hats, sunscreen and all that protective stuff. Pay even more attention to this at altitude. I live at 7,000' plus, and then go up from there - UV exposure at altitude is fast and quite painful.
....
I've mentioned a lot of extra gear here. If you're not going solo, you can split this amongst the group, excepting stuff like the Space blanket (one per person) or the TP (hey, people have to learn some stuff the hard way, and you can't exactly share a limited supply).
I've only needed some of these items once over the years, but that one time made all the extra carrying quite worthwhile for me. Carrying all of it is a bit like car insurance - you don't want to have to do, but you're glad to have it when matters go awry.
As well, the intention is to hike and see the world, not to fret about things left behind.
Hope this helps a bit and maybe gives you a lift. If it doesn't offer that with such a long posting, print it, fold it several times, and then sit on top of it for a different level of perspective... :twisted: :twisted: :lol: :lol: :twisted: :twisted:
John P.