Here are the materials so far in Commonwealth of Massachusetts v. Wampanoag Tribe of Gay Head (Aquinnah) (D. Mass.):

1 Notice of Removal

18 Massachusetts Motion to Remand

21 Opposition to Motion to Remand

25-1 Massachusetts Reply

31 DCT Order

An excerpt:

This lawsuit involves a dispute between the Commonwealth of Massachusetts and a federally recognized Indian tribe as to who has regulatory jurisdiction over civil gaming on Indian lands on Martha’s Vineyard. The Aquinnah Wampanoag Tribe and related entities have taken steps to commence commercial gaming operations on tribal lands without a license from the Commonwealth. The Commonwealth of Massachusetts contends that by doing so, the Tribe violated a 1983 settlement agreement that subject the lands in question to state civil and criminal jurisdiction. Count 1 of the complaint alleges breach of contract, and Count 2 seeks a declaratory judgment.

The Commonwealth filed suit in state court on December 2, 2013. On December 30, 2013, defendants removed the action to this Court on the basis of federal-question and supplemental jurisdiction, 28 U.S.C. §§ 1331, 1367. The Commonwealth has moved to remand the matter to state court. For the reasons set forth below, the motion will be denied.