Here are the materials in DISH Network v. Laducer (D. N.D.):
From the opinion:
This dispute implicates the first Montana exception. Dish Network argues this case involves no activity that took place on the reservation, and that it only concerns the filing of two third-party complaints against Brian Laducer. However, the contract between Dish Network and Brian Laducer lies at the heart of this protracted dispute. In his Tribal Court complaint, Brian Laducer alleges “Dish Network has taken advantage and abused the legal process to harm Mr. Laducer.” Determining whether Dish Network abused the legal process will undoubtedly involve an examination of the contract between Dish Network and Brian Laducer. Dish Network voluntarily entered into a contract with Brian Laducer, an enrolled member of the Turtle Mountain Band of Chippewa Indians, to provide services on the reservation. By entering into a consensual contractual relationship with tribal members on tribal land, Dish Network subjected itself to the jurisdiction of the Tribal Court. This factor weighs against granting a preliminary injunction.
And here are the state court materials leading into the tribal court case (the case started in state court, was removed to federal court, and remanded back to state court, which determined it did not have jurisdiction):