Here are the updated materials in State of Washington v. Tribal Court for the Yakama Indian Nation (E.D. Wash.):
Washington Opposition to Yakama Motion
DCT Order Denying Yakama Motion for PI
The materials from the tribal court portion of this case are here. And the earlier federal court materials on tribal court jurisdiction are here.
Can you post a link to the 1994 agreement as I have not been able to find it?