August 31, 2026.
The Tohono O’odham Nation is asking a federal court to pause construction activity along its Arizona-Mexico border while the Nation appeals a ruling that cleared the way for the Trump administration to proceed with a planned border wall.
The latest legal action comes after U.S. District Judge Richard Leon denied the Nation’s request for a preliminary injunction on August 13, ruling that the Nation had not shown it was likely to succeed in its claims that the project would unlawfully alter reservation boundaries or constitute a trespass. Leon also concluded that the federal government’s interests in border security, immigration enforcement and public safety outweighed the harms alleged by the Nation at this stage of the case.
The Nation has now asked the district court to pause the effect of that ruling while it pursues an appeal before the U.S. Court of Appeals for the D.C. Circuit. In its latest filing, the Nation argues that the federal government has interpreted the ruling as permission to move ahead with activities on or involving tribal land before the underlying legal questions have been resolved.
That concern became more immediate last week.
On August 25, the Nation reported that federal agents and border wall contractors entered the reservation. Tribal officials said armed federal personnel accompanied contractors conducting preliminary work, including soil sampling and drilling at locations along the border. The Nation has maintained that contractors do not have permission to enter tribal land and has warned against trespassing.
According to the Nation, the preliminary work is connected to the planned border wall project, which would replace existing vehicle barriers along approximately 62 miles of the Nation’s border with Mexico. The Nation has strongly opposed construction of a wall, arguing that it threatens sacred places, cultural resources, wildlife habitat and longstanding connections among O’odham communities on both sides of the international boundary.
The dispute centers in part on the federal government’s position that construction can take place within a 60-foot-wide strip known as the Roosevelt Reservation, a federally controlled border buffer established in 1907.
Judge Leon relied heavily on the Roosevelt Reservation in rejecting the Nation’s request for an injunction. He concluded that the federal government had not demonstrated plans to construct outside that area and found that the Nation had not established that construction within the federal strip would legally diminish its reservation boundaries.
The Nation disagrees with that interpretation and argues that the federal government cannot use the Roosevelt Reservation to justify activities that require access across tribal lands.
The situation has also raised concerns about tribal sovereignty. Tohono O’odham Chairman Verlon Jose said federal personnel entered the Nation with contractors despite objections from tribal officials. Tribal authorities have been assessing additional legal options as construction-related activity continues.
The federal government maintains that the project is necessary to address what it considers a significant smuggling and trafficking corridor along the southern Arizona border. U.S. Customs and Border Protection has defended the project as part of a larger effort to strengthen border security.
The planned project is part of the administration’s broader border infrastructure program, which includes steel bollard barriers, roads and surveillance technology. The government has argued that the existing vehicle barrier does not provide sufficient protection against people crossing the border.
For the Tohono O’odham Nation, however, the dispute goes beyond the physical construction of a wall.
The Nation has argued that construction could permanently damage sacred sites and natural resources and interfere with cultural and religious practices. The Nation also has members and communities on both sides of the international border, making border infrastructure a particularly significant issue for the O’odham people.
The August 28 filing represents the latest step in what is likely to become a closely watched legal battle over the relationship between federal border authority and tribal sovereignty.
The district court has not yet granted the Nation’s request to pause the construction-related activity, and the appeal to the D.C. Circuit remains pending.
For now, federal personnel and contractors have begun preliminary work while the Nation continues its legal challenge.
The case could ultimately determine how far the federal government’s authority extends when border security projects intersect with the lands, sovereignty and rights of a federally recognized tribal nation.
