See Dine Citizens, 932 F.3d at 853-56. Maverick also relies upon Alto and Southwest Center for Biological Diversity v. Babbitt, 150 F.3d 1152 (9th Cir. 1998) (per curiam) to argue that the Federal Defendants can serve as an adequate representative of the Tribe. But these cases are inapposite.

As a practical matter, an absent party's ability to protect its interest will not be impaired by its absence from the suit where its interest will be adequately represented by existing parties to the suit. See Southwest Center for Biological Diversity v. Babbitt, 150 F.3d 1152, 1153 (9th Cir. 1998); see also Verity, 910 F.2d at 558. In determining whether an absent party is adequately represented by an existing party, we consider "whether "the interests of a present party to the suit are such that it will undoubtedly make all" of the absent party's arguments; whether the party is "capable of and willing to make such arguments"; and whether the absent party would "offer any necessary element to the proceedings" that the present parties would neglect."

"A non-party is adequately represented by existing parties if: (1) the interests of the existing parties are such that they would undoubtedly make all of the non-party's arguments; (2) the existing parties are capable of and willing to make such arguments; and (3) the non-party would offer no necessary element to the proceeding that existing parties would neglect." Sw. Ctr. for Biological Diversity v. Babbitt, 150 F.3d 1152, 1153-54 (9th Cir. 1998) (per curiam). Application of those factors shows the states' and tribes' interests are adequately represented.

Moreover, the Ninth Circuit has also held, "As a practical matter, an absent party's ability to protect its interest will not be impaired by its absence from the suit where its interest will be adequately represented by existing parties to the suit." Washington, 173 F.3d at 1167 (citing Sw. Ctr. for Biological Diversity v. Babbitt, 150 F.3d 1152, 1153 (9th Cir. 1998)). "A non-party is adequately represented by existing parties if: (1) the interests of the existing parties are such that they would undoubtedly make all of the non-party's arguments; (2) the existing parties are capable of and willing to make such arguments; and (3) the non-party would offer no necessary element to the proceeding that existing parties would neglect."

The moving party has the burden of proving that dismissal is warranted. Shermoen v. United States, 982 F.2d 1312, 1317 (9th Cir. 1992). Although the Tribe contends that it is a necessary party because its interest cannot be adequately represented by the United States, the Ninth Circuit has many times held that the United States may adequately represent an Indian tribe unless there is a conflict of interest between them. Shermoen, 982 F.2d at 1318; Makah Indian Tribe v. Verity, 910 F.2d 555, 558 (9th Cir. 1990); Southwest Center for Biological Diversity v. Babbitt, 150 F.3d 1152, 1154 (9th Cir. 1998); Washington, 173 F.3d at 1167. To prevail on a claim that the United States cannot adequately represent the Tribe's interest, the Tribe must not only identify the alleged conflict but demonstrate how such a conflict might actually arise under the facts of the case.

In Dine Citizens, we distinguished Southwest Center for Biological Diversity v. Babbitt, 150 F.3d 1152 (9th Cir. 1998) (per curiam), which the Districts cite heavily in support of their argument that the Tribes are adequately represented by Reclamation. In Southwest Center, we held that the government was an adequate representative of a tribe in a suit brought to stall the government from utilizing a newly built dam pending further environmental study. 150 F.3d at 1154-55.

While Reclamation and the Tribes share an interest in the ultimate outcome of this case, our precedent underscores that such alignment on the ultimate outcome is insufficient for us to hold that the government is an adequate representative of the tribes. In Dine Citizens , we distinguished Southwest Center for Biological Diversity v. Babbitt , 150 F.3d 1152 (9th Cir. 1998) (per curiam), which the Districts cite heavily in support of their argument that the Tribes are adequately represented by Reclamation. In Southwest Center , we held that the government was an adequate representative of a tribe in a suit brought to stall the government from utilizing a newly built dam pending further environmental study.

We therefore upheld the district court's determination that the Kumeyaay tribes and Repatriation Committee were necessary parties. In Southwest Center for Biological Diversity v. Babbitt , 150 F.3d 1152 (9th Cir. 1998), by contrast, we held that the government could adequately represent a tribe's interest in litigation brought by an environmental organization challenging, under NEPA and the ESA, the Secretary of the Interior's plan to begin using a new water storage facility. Id. at 1153.

Sw. Ctr. for Biological Diversity v. Babbitt, 150 F.3d 1152, 1153-54 (9th Cir. 1998) (citing Shermoen, 982 F.2d at 1318).

SeeSac and Fox Nation, 240 F.3d at 1259 (Secretary's interest in defending decision to acquire tract in trust for tribe and its conclusion that tract was gaming-eligible was virtually identical to tribe's interest in conducting gaming; thus any potential impediment or prejudice to tribe was greatly reduced); Kansas, 249 F.3d 1213 (10th Cir. 2001) (government's interest in defending NIGC's Indian lands determination sufficiently similar to tribe's interest in conducting gaming on land to provide adequate representation). See also, Artichoke Joe's, 216 F. Supp. 2d at 1118 (while tribes could claim a legal interest in lawsuit challenging validity of compacts between tribes and State, they were not necessary parties where their legal interest could be adequately represented by the Secretary); Southwest Ctr. for Biological Diversity v. Babbitt, 150 F.3d 1152 (9th Cir. 1998) (tribe was not a necessary party to suit seeking to halt flooding of area where it had right to store water because Secretary and municipal defendants could adequately represent tribe's interest). The SNI points to no conflict of interest here, but does allege that it is unclear whether the Government will make each and every argument it would make were it a party in the case.