Thank you all for taking the time to comment and make suggestions, I really appreciate it. When I first took the shot I contemplated taking an additional image without the nd filter to freeze the foliage (perhaps I should have), but after a quick review on the lcd (while the camera was still in position on the tripod) I decided I liked the movement. I thought it was interesting to show the movement of the wind, and as an added bonus, not all of the vegetation is blurred. I liked the contrast between the blurred and non-blurred foliage.
As an experiment I tried cropping the top off a little, but I felt it became to cramped.
MattBurt, thank you for the suggestion to check the leveling. I used the level built into the camera when I took the shot, however, I have always wondered how accurate that level really is. Once I have a little more time I will go back and see if tilting the image helps.
Colorado David, I recommend checking the park out. It really is a very nice park, and as an added bonus, there is a nice little restaurant inside the park that sits next to the falls. I can recommend their fish tacos followed up with a nice beer!
