Nikon zoom lens for thru-hiking the Appalachian Trail

I don't recommend either of the 24-120mm lenses. I've read poor reviews of the D version and have experienced first-hand the poor sharpness of the VR version. My Nikkor 28-105mm f3.5-4.5 is MUCH sharper, and has a pretty good (1:3) macro setting, for a zoom lens. Love the F100. Metering was always spot-on for my Velvia 50 slides.

Are you going to shoot transparency or neg film?

My choice would be 24, 50 and 105mm lenses and a 1.4x telextender. And as suggested - the lightweight AF plastic versions of the lenses. I am just not a fan of zooms: more of a 'fast glass/slow film' shooter.

Weight is a most important factor for hiking, and I don't know that Nikon makes especially light cameras, certainly mine aren't. The old Canon Rebel was a light weight wonder - though one body may not make it through the entire hike.

I had the 24-120 VR and it was not a good lens. Soft, focus problems,heavy etc. I didn't like it.

If I was going for a hike like that, I'd just get a 35/2, 85/1.8, and some tele lens.

Don't worry, B. We're just living vicariously through you.

Definitely read A Walk in The Woods. Lens wise if you were thinking to carry a converter and change it all the time when you need it you may as well carry two light primes. Zoom with your feet.

For a fast tele prime, the Nikkor AIS 200mm f4 is small, light and sharp!

While for most long-distance walks I've gone over to the dark side for weight reasons (a D*** P&S), my lightest-weight & most compact walking film kit is a rangefinder.

Lenses are tiny (I carry 21 + 35 + 90 & sometimes a 15mm), also lighter (though the Leica M6 itself isn't as light as its size would indicate). The cheaper & lighter CV bodies could be a way to go.
AF, motorized advancement, long lenses & batteries are no-nos on long walks.
For landscapes & photographing the people you meet you won't need lots of automation & fast frame rates.
But you *will* feel every gramme you're carrying!