From the Seattle Times:
Expand tribal police authority
As more and more non-Indians work, play and shop on tribal land, there is a serious imbalance in the legal ability to maintain law and order.
House Bill 2476, and a companion measure in the Senate, would give tribal police departments the authority to arrest non-Indians on tribal land. The legislation deals with the reality of skyrocketing contacts across economic and sovereign boundaries.The intent is straightforward. Tribal police officers would have the powers of any other Washington peace officer to enforce state laws and make arrests.