Arizona v. Navajo Nation

In Arizona v. Navajo Nation, decided on June 22, 2023, the U.S. Supreme Court addressed whether the 1868 Treaty of Bosque Redondo obligated the federal government to assess and secure water rights for the Navajo Nation. The tribe, residing on a vast reservation spanning Arizona, Utah, and New Mexico, sought to compel the United States to identify its water needs and develop a plan to meet them, particularly from the lower Colorado River. The states of Arizona, Nevada, and Colorado intervened, opposing the claim amid a prolonged drought straining the river basin. In a 5-4 ruling authored by Justice Brett Kavanaugh, the Court held that the treaty did not impose an affirmative duty on the federal government to take active steps to procure water for the tribe, reversing a lower court decision that had allowed the lawsuit to proceed.

The Supreme Court ruled 5-4 against the Navajo Nation, holding that the 1868 treaty does not impose a duty on the United States to take affirmative steps to secure water for the tribe. The Court found the treaty establishes a duty to secure entry to the reservation but no duty to actively manage or provide water resources.

Whether the 1868 Treaty establishing the Navajo Reservation requires the federal government to take affirmative steps to assess the tribe's water needs and develop a plan to secure those needed water resources.

The ruling significantly constrains the scope of the federal trust responsibility regarding natural resources, forcing tribes to rely on administrative and political processes rather than immediate judicial relief for water claims. It heightened tensions in the drought-stricken Colorado River Basin, where competing claims among states and tribes remain unresolved. The decision also prompted criticism from tribal advocates, who argued it leaves the Navajo Nation with limited legal avenues to address systemic water scarcity affecting tens of thousands of residents, reinforcing debates about historical inequities and federal obligations to Native American communities.