Lower court materials here.
Here are the materials in Oglala Sioux Tribe v. United States (D.S.D.):
Here is the complaint in Northern Cheyenne Tribe v. United States (D. Mont.):
Here are the materials in Hawk v. Burr (E.D. Wis.):
By Dana Hedgpeth, former board member of the Native American Journalists Association. Here.