At the end of the boardwalk (going inland) there's an eagle's nest and usually eagles nearby. Can you see the eagle in the trees? Hint: look for the white head. (You probably have to click on the picture to enlarge and focus it.)
Here's a closer shot. In the one above there's a white tree trunk in the middle. The eagle's in the cottonwood tree to the left of it, a little above the the midline.