I am not sure....any ideas???
American Bittern or Immature Green-backed Heron...I did get a brief glimpse of one of the parents and it was fairly colorful.
To see more bird images click: HERE 2011_08_07_0008_1 crop.jpg
I believe it's an adult green heron (pg 111 NG fifth edition Field Guide to Birds of North America. I also have some shots on my site under Herons/Green Herrons.