Excellent capture-- but ah, what a bit of sharpening would have done for this image. I would have used something like USM 80%, 0.5 radius, 0 threshold.
Don't care for the yucca right in the middle of the frame. Would have tried to frame the background if possible. Otherwise nice, especially I like the sky.
Having spent a little time reading up on Ansel and looking through his work I now appreciate the 'style' more than I did for my own entry! (so I screwed up a little!)
This entry however is very much along the right lines, excellent work.
You found a great spot for this...and made the most of it. Great b/w tones IMO, with detail evident and nothing blown out. Good composition and interest to this viewer anyway. I'm not an Ansel expert, but I believe this is a great photo for the challenge and in its own right.
Good adams-like landscape shot selection and it has nice clouds in the sky. The image, however is very soft focused. Adams is known for his tack sharp images with very deep DOF.