Utah? Antelope canyon comes to mind, there is another one.
I was thinking of visiting that when in Flagstaff last year but didn't want to drive those extra few hundred miles. Time was a factor too, just spent two days in the canyon instead.
2000 740i-Annalisa and 2008 335i-Weebl. Weebl may wobble but has DTC
2012 X5d in Sparkling Bronze ( The Ultimate Cat Carrying Machine)