25 CFR 163.4: Secretarial recognition of tribal laws.

Subject to the Secretary's trust responsibilities, and unless otherwise prohibited by Federal statutory law, the Secretary shall comply with tribal laws pertaining to Indian forest land, including laws regulating the environment or historic or cultural preservation, and shall cooperate with the enforcement of such laws on Indian forest land. Such cooperation does not constitute a waiver of United States sovereign immunity and shall include:

(a) Assistance in the enforcement of such laws;

(b) Provision of notice of such laws to persons or entities undertaking activities on Indian forest land; and

(c) Upon the request of an Indian tribe, the appearance in tribal forums.