This place is still on my list to photograph. Shame on me for never going and I live in the state. I like the tones throughout the canyon as they appear pastel like. The upper right ridges seem a little too contrasty and my eyes keep getting drawn to that. I think here I would have chosen a vertical comp and include more of the river as well. The cliffs in the back have some very nice light on them as well.
The upper-right ridges are actually where the direct sun was hitting them most. So, naturally, juxtaposed the rest of the scene that has little contrast due to shading, it's bound to look a little biting.
I also considered a vertical composition. However, for many reasons, I opted for the horizontal, "landscape," crop, instead.