On June 22, 2023, the U.S. Supreme Court issued its opinion in Arizona v. Navajo Nation, 599 U. S. ____ (2023), holding that the federal government is not required to affirmatively secure water for the Navajo Nation. At the heart of the case was an 1868 treaty between the U.S. and the Navajo Nation, which established the Navajo Reservation. Under the treaty, the reservation includes “the land, the minerals below the land’s surface, and the timber on the land, as well as the right to use needed water on the reservation.” Navajo Nation, slip op. at 1. The Navajo Nation asserted a breach-of-trust claim against the federal government, arguing that the treaty requires the U.S. “to take affirmative steps to secure water for the Navajos—for example, by assessing the Tribe’s water needs, developing a plan to secure the needed water, and potentially building pipelines, pumps, wells, or other water infrastructure—either to facilitate better access to water on the reservation or to transport off-reservation water onto the reservation.” Navajo Nation, slip op. at 2.

In a 5-4 decision authored by Justice Kavanaugh, the court concluded that while the 1868 treaty allocated a reservation for the Navajo Nation’s use and occupation, the treaty did not contain any language imposing a duty on the U.S. to take affirmative steps to secure water for the tribe. According to the court, to maintain a breach-of-trust claim, the Navajo Nation needed to establish that the language in a treaty, statute, or regulation imposed certain duties on the U.S., as “[t]he Federal Government owes judicially enforceable duties to a tribe ‘only to the extent it expressly accepts those responsibilities’” via one of these instruments. Navajo Nation, slip op. at 7. The court found that the treaty did impose a number of specific duties on the U.S. (e.g., constructing certain buildings on the reservation; providing teachers, articles of clothing, or other goods; and supplying seeds and agricultural implements), but the treaty said nothing about any affirmative duty to secure water. Navajo Nation, slip op. at 8.

The court acknowledged that the U.S. “maintains a general trust relationship with Indian tribes, including the Navajos”; however, the U.S. “is a sovereign, not a private trustee,” meaning that it does not assume all the fiduciary duties of a private trustee. Navajo Nation, slip op. at 9. Therefore, the court declined to infer duties not found in the text of a treaty, statute, or regulation. Ultimately, the court deferred to congress and the president to enact “laws to assist the citizens of the western United States, including the Navajos, with their water needs.” Navajo Nation, slip op. at 2.

Justice Thomas authored a concurring opinion. Justice Gorsuch authored a dissenting opinion, joined by Justices Sotomayor, Kagan, and Jackson.