Saw these at Arrick's Shop in West Yellowstone.
Thought they were quite interesting.
http://i1101.photobucket.com/albums/...ps9f51a507.jpg
This one is not quite in focus, but I think you can make it out. Flavs were on the water on the upper Henry's Fork.
http://i1101.photobucket.com/albums/...ps64fba47f.jpg