Ok, I did it: This is heavily photoshopped! I pasted the foreground into a "sky"-image The original shot can as well be seen in my folder, but the sky was just boring.
I took a nice thunderstorm sky from a grandcanyon shot and merged both images. I hope you excuse for this! I just wanted to know how the Death Valley shot would have looked like with a more interesting sky, thats why i tried this. I do not want to deceive anyone. I like the outcome and would be glad to have some feedback...