The United States has filed an amicus curiae brief confirming that the trial court erred in disregarding the NIGC’s action.  The United States confirmed that the state courts are required to defer to the agency’s views, as expressed in an NIGC opinion letter, the Chairman’s decision disapproving the agreement, and in the United States’ amicus brief, itself:

[T]he Superior Court was obliged to exercise its jurisdiction consistent with IGRA and IGRA’s bar on the enforcement of unapproved management contracts. Instead of acknowledging this bar and the need to resolve whether the ELA was an unapproved management contract (consistent with deference principles), the Superior Court simply denied the Tribe’s motion to dismiss on the grounds that the Chairman’s 2009 Disapproval was not “final agency action” binding on the state court. . . .

This is a non sequitur. A final disapproval decision by the NIGC is not necessary to render an unapproved management contract void. Such contract is and remains void unless and until the NIGC takes formal action to approve the contract. 25 C.F.R. §§ 533.1(a), 533.7. The NIGC’s disapproval of the ELA merely preserved the legal status quo. Thus, even if the 2009 Disapproval was invalid due to procedural errors – a question over which the Superior Court had no jurisdiction (see infra) – a ruling setting aside the NIGC’s decision would not resolve the preemption question.

. . .

[T]he present case involves the NIGC’s determination on a threshold legal issue involving an interpretation and application of the NIGC regulation defining “management contract.” The NIGC expressed its regulatory interpretation in the 2009 Disapproval and the 2007 OpinionLetter (as well as in the present amicus brief). The NIGC is entitled to deference in the interpretation of its own regulations, even when such interpretation is not rendered in a formal rulemaking or other final agency action.

Here is the United States’ brief and the parties’ briefs in response:

United States’ Amicus Brief

Sharp’s Response to United States’ Amicus Brief

Tribe’s Response to United States’ Amicus Brief

The merits briefs are here.