It's likely just the perspective of the bridge but it makes the image look unstraight - I feel my head tilting to straighten up the line of the bridge. Of course straightening up the bridge makes the horizon uneven so I think maybe a different angle of the bridge may have been better.
Did you know the same guy who designed this bridge, built the George Washington Bridge? I have a few images shot from this same park in my portfolio. Guess you shot this early in the morning. You can see more on my PAD blog. See my profile. Let me know if you want to go shoot together sometime.
Very nice shot just need a litle color here, very sharp and crisp.
Well, there are bridges over canyons were there is no water underneath :-). You have taken this picture from a difficult angle, tilting. I think I would have cropped it, the bridge placed a little higher or a little lower, and tried to do something about the sloping.