Here are the recommended links for learning about bison bones.
The first is Larry Todd’s excellent page from Colorado State: http://lamar.colostate.edu/~lctodd/bison.htm
This is from Wyoming and is good for photos and QuickTime movies: http://www.uwyo.edu/reallearning/bisonindex.html
Anyone working on a bison kill site should have at least a little familiarity with the skeleton. Send me links if you have other suggestions.