Here are the materials in Herrera v. Alliant Specialty Insurance Services (D. Colo.):
From the order:
In this case the plaintiff alleges that she was employed by the Southern Ute Tribe and the Southern Ute Tribe Growth Fund. However, she does not specify whether her employment was within or outside the confines of the reservation. The defendants seem to assume that the plaintiff’s employment was within the confines of the reservation. However, the defendants do not provide any declarations or other evidence to support this assumption. The locus of the plaintiff’s employment is a potentially pivotal jurisdictional fact.
The issues outlined above relate directly to the court’s subject matter jurisdiction. Those issues must be resolved before the court may address other issues presented in the motion to dismiss. Thus, I deny the motion without prejudice and grant  the defendants an opportunity to file a renewed motion that addressing the issue of subject matter jurisdiction. To the extent specific facts are relevant to the determination of the court’s subject matter jurisdiction, I note that the “court has wide discretion to allow affidavits, other documents, and a limited evidentiary hearing to resolve disputed jurisdictional facts under Rule 12(b)(1).” Holt v. United States, 46 F.3d 1000, 1003 (10th Cir. 1995). If the defendants choose to file a renewed motion to dismiss, I direct the defendants to address the scope and limits of tribal jurisdiction, as outlined in Montana v. U.S., 450 U.S. 544, 565 (1981), MacArthur v. San Juan County, 497 F.3d 1057, 1068 (10th cir. 2007), and related cases. Of course, the analysis of this issue must be focused on the jurisdictional facts of this case.