just so you know, Sitting Bull wasn't a tribe leader. he was a medicine man.
I knew he was a medicine man, but...
In approximately 1867, Sitting Bull became the first principal chief of the entire Sioux nation. Shortly thereafter peace was made with the U.S. government, although Sitting Bull refused to attend the peace conference or sign the treaty.
http://www.incwell.com/Biographies/SittingBull.html
I also thought he was a Hunkpapa chief prior to that, as well.