Photographing the Grand Canyon can be tough, especially under certain lighting conditions. I feel that you might have been able to get a little more clear DOF in this one, but I love the sky and the composition is very good as well.
It's a very nice picture of the canyon, and believe me, I've seen plenty since I live in the Grand Canyon State. A good clear day is always a plus when photographing this magnificent hole in the ground. Good Job!