Neilhunt

I really enjoy the Zeiss Batis 18mm on my Sony (full frame) for landscapes.

Even if that recommendation isn't helpful to the OP, this observation might be: the perspective distortion from an UW is often objectionable on a landscape.

I have learned always to point the camera horizontal (horizon across the midline), which makes verticals vertical, instead of tilting inward or outward. However, I usually like the aesthetic of horizons on the thirds (either one third sky, or two-thirds sky - if the clouds are cool), and to achieve this, I crop in post.

The alternative is perspective correction in LR, which still requires shooting with the post processing in mind, since fixing tilting vertical lines narrows the top or bottom of the shot, and alters the height of the picture.

Make a bunch of practice shots before your big trip, and be sure to examine the results on a computer while you can try again.

cjc2 Loc: Hellertown PA

Quite a bit more, actually!

DRG777 Loc: Metro Detroit

For most landscapes I use a 16-35 on a full frame.

raferrelljr Loc: CHARLOTTE, NC

I would say the Nikon 16-35 F4 WA zoom.

Architect1776 Loc: In my mind

I would go the 10-20mm. Great price and an interesting review that praises this lens. http://www.kenrockwell.com/nikon/10-20mm.htm
I have the Canon equivalent 10-18mm and love it for the type of use you are wanting to put it to.

lastshotmike

We made a trip last year to the 5 parks in southern Utah, Monument Valley and the Grand Canyon. I have a D7200 and brought my Nikon 10-24 and 16-85 thinking as you have that the wide angle 10-24 would be the winner. The 16-85 is what I used almost all the time. The 10-24 was too limiting. I think your 24-120 is the right lens on your full frame. You need the range to get the shots. My opinion.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Actually, when you use an ultra wide lens for landscape, the tendency is to shoot sweepingly wide views, and you end up cropping foreground and/or sky to get a "closer" view and often a more meaningful, less "wide angle looking" composition. You still have the dilemma of odd-sized mat windows and picture frames, but most framing shops will accommodate pano shots. Bay Photo offers the following pano style sizes:

3.5x10
4x10
4x12
5x10
5x14
5x15
5x20
5x30
and so on, all the way up to a 30x120.

And they offer custom sizes as well.

Frame Destination offers the following frame sizes and mats for panos:

8" x 16"
8" x 24"
10" x 20"
11" x 17"and 12" x 18"
12" x 24"
12" x 20"
12" x 28"
12" x 36"and 13" x 38"
16" x 26"and 20" x 30"
16" x 36"
18" x 30"and 20" x 32"
16" x 40"
24" x 40"

And the also offer custom sizing.

I had a Sigma 10-20 F4-5.6 - it was an exceptionally good lens. But once the novelty wore off, it got used only occasionally, usually in close quarters. Never liked it much for sweeping landscapes.

Architect1776 Loc: In my mind

This is where there is absolute confusion on the WA lens. It is not a panacea for sweeping wide landscapes as the objects are rendered infinitely small. It does come in great if you know how to use it and in places like Antelope Canyon, close-ups of a child on the rim of the Grand Canyon and innumerable situations where the WA shines you can't beat the thousands of great shots that it can allow you to do. As with most lenses beyond 28-100 mm range and especially the WA range, though it requires a bit of thought to use besides just point and mindlesly shoot.