Here is the opinion in K2 America Corp. v. Roland Oil & Gas Co.
Here is an excerpt:
In this appeal, we consider whether federal jurisdiction exists over a lawsuit between two Montana corporations alleging state law claims arising from a dispute over lands held by the United States in trust for various Indian allottees. We conclude that federal jurisdiction does not extend to the claims, and we affirm the judgment of the district court.
The district court properly dismissed this case for lack of subject matter jurisdiction. We need not—and do not—reach any other issues raised by the parties, including exhaustion of tribal remedies. We note, though, that our holding does not preclude K2 from seeking relief in Blackfeet Tribal Court. See, e.g., Longie, 400 F.3d at 591. “Indeed, there may be circumstances in which a nonmember plaintiff may have no forum other than the tribal courts in which to bring his claims.” Smith v. Salish Kootenai Coll., 434 F.3d 1127, 1140 (9th Cir. 2006) (en banc).
And here are the briefs: