October 22, 2026.
A federal judge in Washington, D.C., has denied the Tohono O’odham Nation’s request to halt border wall construction along its Arizona reservation while it appeals an earlier ruling, leaving the federal government free to proceed unless another court intervenes.
The decision comes months after U.S. Customs and Border Protection (CBP) added the Nation’s international boundary to its Smart Wall construction plans, despite an April 2025 presidential memorandum that expressly excluded Federal Indian Reservations from a specific federal military land-use initiative along the southern border.
The dispute raises questions about the scope of the memorandum, the federal government’s authority to build barriers on tribal land and the Nation’s ability to protect its sovereignty, cultural resources and traditional connections across the U.S.–Mexico border.
Presidential memorandum excluded reservations from military land-use initiative.
On April 11, 2025, President Donald Trump issued National Security Presidential Memorandum 4, titled “Military Mission for Sealing the Southern Border of the United States and Repelling Invasions.”
The memorandum directed federal agencies to arrange for Defense Department use and jurisdiction over designated federal lands along the southern border, including the Roosevelt Reservation, while expressly excluding Federal Indian Reservations from that provision.
The exclusion did not establish an unconditional, permanent prohibition on all border wall construction on tribal lands under every federal law. Instead, it addressed the specific military land-use arrangements established by the memorandum.
That distinction became important as the administration pursued additional border infrastructure under separate federal authorities.
Billions in border funding expanded construction plans.
On July 4, 2025, Trump signed the One Big Beautiful Bill Act, which provided approximately $46.5 billion for border barrier construction and related infrastructure.
The funding gave CBP substantial resources to develop border projects involving physical barriers, access roads, lighting, cameras and detection technology.
These appropriations operated alongside existing federal border-security laws and statutory provisions allowing the waiver of certain legal requirements for border construction.
The new funding provided a separate basis for advancing barrier projects beyond the particular military land-use arrangements addressed in the April 2025 memorandum.
February 2026: CBP adds the Nation’s land to Smart Wall plans.
In February 2026, CBP updated its Smart Wall map to include planned barrier construction along the Tohono O’odham Nation’s approximately 62-mile international boundary in southern Arizona.
The proposed project would replace the existing vehicle barrier with a more substantial border wall and associated infrastructure.
The Smart Wall program can include steel bollard barriers, secondary barriers, patrol roads, lighting, cameras and detection systems. It is designed to combine physical barriers with electronic surveillance and other border-security technology.
The map update brought the Nation’s border into the administration’s construction plans, prompting concerns about how the federal government intended to proceed despite the April 2025 memorandum’s exclusion of reservations from the military land-use initiative.
The map update alone does not establish that the memorandum was formally rescinded or that the government had resolved the legal questions surrounding construction on the reservation.
Nation challenges the project.
The Tohono O’odham Nation has opposed the proposed wall, citing tribal sovereignty, land rights, cultural resources and the potential disruption of family and ceremonial connections across the international border.
The Nation’s homeland extends across what is now southern Arizona and northern Mexico. The international boundary divides communities whose family relationships, traditions and cultural practices predate the modern border.
Tribal leaders have also raised concerns about damage to sacred places, water resources and other culturally significant areas.
The Nation has maintained that the federal government cannot proceed as planned without respecting its rights and legal protections.
In June 2026, the Nation sued federal officials in the U.S. District Court for the District of Columbia. Its claims included arguments that the project would trespass on sovereign tribal land and effectively alter reservation boundaries without congressional authorization.
The federal government has maintained that it possesses authority to carry out the project under applicable border-security laws and congressional appropriations.
Federal courts decline to halt construction.
On August 13, 2026, U.S. District Judge Richard J. Leon denied the Nation’s request for a preliminary injunction to stop the project while the lawsuit proceeded.
The court concluded that the Nation had not established a sufficient likelihood of success on its claims at that preliminary stage, including its arguments concerning reservation boundaries and trespass.
The Nation continued its legal challenge and sought to prevent construction while appealing the ruling.
On October 8, Judge Leon denied that request as well, finding insufficient grounds to issue an injunction pending appeal.
The October decision did not resolve the entire lawsuit. It denied the Nation’s request for emergency relief while the appeal continues.
The federal government therefore has not been barred by the district court from proceeding with the project, although further court action could affect construction.
Construction preparations documented.
Construction preparations have raised additional concerns among tribal leaders and community members.
An October 10 investigation by ProPublica reported that federal officials notified the Nation in August that contractors would conduct soil testing for the project. Contractor vehicles, drilling rigs and Border Patrol vehicles subsequently traveled near the Tadai Me prayer camp, where community members have gathered to pray in opposition to the wall.
The publication also documented community reports of drones, surveillance and encounters with federal officers near the camp.
These reports describe activities surrounding the project, but they should not be taken as proof that all planned wall sections have been completed or that every reported construction activity occurred on reservation land.
Photographs and videos documenting contractor vehicles, drilling equipment and site preparations are available through the Nation’s official No Wall page and media reporting.
The Nation’s concerns extend beyond the physical barrier itself to the potential effects of construction and surveillance on tribal members, cultural practices and access to important places.
Appeal leaves major questions unresolved.
The Nation’s appeal is proceeding in the U.S. Court of Appeals for the D.C. Circuit. The case has received expedited consideration, with briefing scheduled to conclude October 21 and oral argument scheduled for December 2026.
The central legal question is not simply whether the April 2025 memorandum prohibited a wall. The memorandum expressly excluded Federal Indian Reservations from a particular military land-use initiative, but the administration has pursued the proposed wall under other claimed legal authorities.
The courts must consider the Nation’s legal claims in the context of those authorities, the relevant federal statutes and the protections applicable to tribal lands.
The case could have implications for other federally recognized Tribal Nations whose lands border the United States’ international boundaries.
For the Tohono O’odham Nation, the immediate issue remains whether construction can proceed while its challenge is pending and whether the courts will ultimately accept its arguments concerning sovereignty, land rights and the federal government’s authority.
The district court has so far declined to halt the project. The broader legal dispute remains unresolved.
