Tetons_v38c.jpg is my favorite, though I like the first too. It's an incredibly gorgeous scene and very well framed. But a couple of things don't look quite right to me at the same time. I hope you don't mind the critique, all three of these have tremendous potential, and it's clearly taken a lot of skill to even get here.
With that in mind:
In the first image what stood out to me most was the water (river, or lake? looks too big to be Snake River, but I'm not aware of a lake with this perspective either?). It either looks too patchy, the patch edges are too sharp, or the patches are too rough/reflective, or... something. The water just doesn't look right to me, in all 3 to varying degrees. Hard to say without a reference shot from that location. Are you working from specific reference? This is the patchiest photo I found of the area:
https://www.outdoorproject.com/sites/default/files/styles/cboxshow/public/blog-copies/dsc_7454_5_6.jpg?itok=Q2tXXgb4The second thing is the rock of the mountains just look too smooth, like minimal or no displacement detail was added on top of the (presumably quite high resolution) DEM. It may be tough to get realistic displacement shapes but I think it would help realism a good deal, especially in that 2nd/middle image.
Looking forward to seeing if you evolve these.
- Oshyan