Here are updated materials in State of Washington v. Yakama Nation Tribal Court (E.D. Wash.):
DCT Denying Motion to Dismiss for Ineffective Service
DCT Order Denying Motion to Compel Arbitration
Yakama Motion to Compel Arbitration
Yakama Motion to Dismiss for Ineffective Service
State Opposition to Yakama Motions
Yakama Reply on Ineffective Service Motion
Prior posts are here and here. The case is pending in the CA9 — materials here.