A buddy and I were looking at a swamp on Spring Creek in Spring, Texas on 6 July 2012. We were standing on shore looking around. I spotted one alligator and lots of beautiful dragonflies. Across the swamp, directly in front of us. We both watched the largest bird we had ever seen take flight from a tree and head directly for us. It was gray with no feathers. It had a wing-span of just over 3/4 the length of a pick-up truck and looked like a flying leather "V." It made a sharp right and landed in a tree. Its weight shook the entire top of the tree and from there we lost site. It had a white head, gray wings, and no noticeable feet. The wingspan has to be between ten and fifteen feet and had no feathers, only what appeared to me hide like a bat.
You may add this to your site. We would like to know what we saw. The photos on your site match the description of a huge, leather flying "V," and that best describes what we saw.