I would suggest applying some Unsharp Mask at 10 percent, 150 pixel radius, threshold 0. That will add local contrast without appreciably "sharpening" anything. I think the photo is suffering from some environmental haze effects, so one pass at 10%-150 pixels-0 Threshold might make it look better. You could also apply a second pass of USM at the above settings, and fade it a bit too; I sometimes use two passes of USM this way to boost local contrast in a way that's easy to do and pretty controllable.
Derrel
