Before Trump won his first election, in 2016, with promises to “build the wall,” Arizona’s border with Mexico already had the most barriers of any U.S. state. But an unfinished stretch lay along the southern boundary of the Tohono O’odham Nation, a reservation the size of Connecticut. Now Trump is trying to fill that line in, by ordering a wall built across a 62-mile-long stretch of reservation land. This would constitute what the chairman of the nation, Verlon Jose, called “the biggest land grab of the modern era.” The federal government, he told me, “hasn’t unilaterally tried to take Indian lands like this in a very long time.”Cranes began putting massive steel panels in place in the San Rafael Valley last fall. From there, construction headed west toward the Tohono O’odham Nation. Jose had several meetings with local and federal officials, but the tribe’s objections to the wall were ignored. The Department of Homeland Security informed Jose that it planned to award contracts for construction by the end of this month, and contractors began touring the reservation. Concluding that legal action was its only option, the Tohono O’odham filed a lawsuit in the U.S. District Court for the District of Columbia against DHS Secretary Markwayne Mullin, U.S. Customs and Border Protection Commissioner Rodney Scott, and U.S. Border Patrol Chief Rosario Vasquez.[Read: The ‘big black scar’]The tribe is asking for an injunction that would stop construction of the border wall on their land. Losing, Jose said, would be a devastating blow, not only to the Tohono O’odham, but to all future claims of Indian sovereignty.The Tohono O’odham’s legal case argues that the reservation is private rather than public land, so the federal government is overstepping its authority by disregarding opposition from the Tohono O’odham, and trespassing on sovereign land; and the proposed border wall would destroy the traditional spiritual, kinship, and economic practices of the Tohono O’odham.In 1907, Theodore Roosevelt issued a proclamation creating a 60-foot strip of public land stretching from California to New Mexico “as a protection against the smuggling of goods” to and from Mexico. This proclamation did not extend to registered native reservations, a fact that Trump acknowledged in a 2025 memorandum on “sealing the southern border.” He directed the secretaries of the interior, agriculture, and homeland security to “provide for the use and jurisdiction” by DOD over federal lands “including the Roosevelt Reservation and excluding Federal Indian Lands” (emphasis mine). Despite recognizing this distinction, the Trump administration has proceeded with the plan to use Tohono O’odham land for the wall as if it belonged to the federal government.The Tohono O’odham’s lawsuit argues that its aboriginal land could become public only if Congress “extinguished” the tribe’s rights to it, which has never happened. Moreover, the federal government has consistently upheld Tohono O’odham land rights. Woodrow Wilson established the Tohono O’odham Reservation with two executive orders, one in 1916 and another in 1917. The following year, Congress ratified the reservation. In 1927, federal law was amended to make clear that “changes in the boundaries of reservations created by Executive order, proclamation, or otherwise for the use and occupation of Indians shall not be made except by Act of Congress.”The Tohono O’odham had inhabited its land for hundreds of years before Mexico, through the 1854 Gadsden Purchase, ceded some of it to the United States. The Mexican-American War had left Mexico in dire financial straits; to pay down its debts, the Mexican government agreed to sell about 30,000 square miles of land in Arizona south of the Gila River, and in New Mexico west of the Rio Grande, for $10 million (about $400 million today). The new border divided the Tohono O’odham in two.For several decades, there were no markers showing where the United States ended and where Mexico began. Only in the late 19th century did the United States and Mexico demarcate the international line with small stone obelisks that looked like miniature Washington monuments. They’re still there today. Over the decades the O’odham placed some barbed wire along the border to keep livestock from straying into the neighboring country, limiting the spread of maladies such as foot-and-mouth disease and hindering cattle thieves.Geraldo L. CadavaBollard and wire border fence, in front of one of the concrete obelisks placed along the border in the 1890s.Then came 9/11. Jose began hearing about the government’s interest in building a wall. Where previously there had been only two or three Border Patrol officers on the reservation, soon there were hundreds. The number of migrants crossing the border also began to surge, here and elsewhere. Traffickers would sometimes abandon their vehicles on O’odham lands. The tribe had to pay for tow trucks to remove them—as well as for medical care for any smugglers and migrants who were injured in the area, and for autopsies for those who were found dead.[Read: ‘Maybe DHS was a bad idea’]Some O’odham wanted the federal government to help manage the border. Some feared that if they didn’t come to an agreement, the government could try to cut federal funds on which the O’odham rely on to pay for schools, roads, housing, and food assistance, even though those funds are legislatively mandated. And others largely oppose the presence of Border Patrol agents entirely, who routinely mistake them for migrants. Ultimately, the O’odham in 2006 reached a compromise: They would accept vehicle barriers to prevent cars and trucks from crossing the border, but not a solid wall.The result was a combination of steel posts and surveillance towers that allow people to cross the border relatively unimpeded, so long as they travel on foot, carry their tribal identification card, and notify the Border Patrol in advance. This is what the Trump administration now wants to replace—with a double border made up of 30-foot-tall steel panels.On the day in March that I met with Jose, he picked me up in a grocery-store parking lot in Sells, the capital of the Tohono O’odham Nation. I climbed into his blue Chevy Tahoe, and we drove to the San Miguel border crossing, about half an hour south. As we approached the border, he pointed to a fenced-in joint-law-enforcement center, shared by DHS and the Tohono O’odham Police Department. He explained that the buildings were trailers for migrant detainees and dorms so that Border Patrol agents wouldn’t have to return to regional headquarters in Tucson or Casa Grande, almost two hours away, after a day’s work. There was also a surveillance tower with cameras. We parked not far from the vertical steel barriers. Agents approached us, curious, then left us alone once they recognized Jose.All along the border, people move back and forth to shop, visit family members, or attend school, but for Tohono O’odham in the United States and Mexico, the ability to cross the border is integral to holding their community together. Today, about 34,000 enrolled O’odham live in the United States; 3,000 live in Mexico. A wall, Jose explained, would disrupt O’odham cultural, spiritual, economic, and kinship practices including funerals, family visits, and trade. Mexican O’odham attend schools, send and receive mail at post offices, and seek medical services in Sells.One O’odham man who lives in Mexico, just on the other side of the border, crosses every day to fill water tanks and haul them back to his ranch, Jose said. He told me about the funeral of an elder that had taken place only two days before I visited him. The man died in Arizona, but wanted to be buried “at home” in Sonora. A procession of vehicles accompanied the body to the border, where a group of O’odham carried the coffin from the car in Arizona to another car in Sonora, and then the procession continued to the cemetery.Baboquivari Mountain, on the reservation in Arizona, is the tribe’s spiritual center—home to their Creator, I’itoi. In late February, Tohono O’odham hold the Baboquivari Run, during which they gather in Pozo Verde, Sonora, and run to the mountain. (Border Patrol officers prop the gate open as the runners cross from Mexico to the United States.) October 4 is the culmination of the Magdalena Pilgrimage, which involves hiking to the church of the town’s patron saint, San Francisco Javier, in Sonora. The lawsuit describes the tradition of praying to the Sea of Cortez to “take away our sickness and grief,” and how each year boys run “along traditional sacred paths marked by important religious landmarks.” The Trump administration’s proposed border would make these practices exceedingly difficult if not impossible.Geraldo L. CadavaChairman Verlon Jose, at the San Miguel border crossing on the Tohono O’odham reservation.[Read: Every state is a border patrol state]The federal government had assured the Tohono O’odham that the impact of any construction would be minimal, and that human remains, man-made rock formations, flowing streams, and archaeological findings would be left untouched. But in May, Customs and Border Protection acknowledged that a contractor hired by the federal government had “inadvertently disturbed” a thousand-year-old sacred site still used for spiritual ceremonies called Las Playas Intaglio. The 200-foot-long geoglyph looks like a fish carved into the desert floor, its nose pointed toward the Sea of Cortez. Photos posted online now show a wide path bulldozed right through the middle of it.When California-bound white settlers crossed Tohono O’odham territory in the 19th century, Jose told me, his ancestors welcomed them. The Tohono O’odham have continued to welcome outsiders, including the federal government, even when those outsiders have sought to exert further control over the O’odham’s ancestral homelands.According to Jose, the Tohono O’odham are as concerned about the security of their nation, and of the United States, as Trump is. Jose noted that many Tohono O’odham have served in the U.S. military. Federal agents patrol Tohono O’odham lands every day. The tribe established the Shadow Wolves, the first all-Indian DHS auxiliary group that helps secure the border. They spend millions of dollars a year on border enforcement. Whenever Customs and Border Protection comes and says, “We want to do this and this,” Jose told me, the Tohono O’odham have cooperated, even if the new systems create what he described as “layers of redundancy.” He added that, in part because of their cooperation, migrant crossings on O’odham land have plummeted by more than 95 percent over the past couple of years, and most of the fentanyl that enters Arizona comes through urban ports of entry, especially Nogales.The lawsuit filed by the Tohono O’odham is a test of whether the sovereignty of native nations is real or imagined. Asked for comment, a DHS spokesperson responded, “Secretary Mullin is a citizen of the Cherokee Nation and made clear during his confirmation hearing that he respects tribal sovereignty.” The statement added: “DHS values its relationship with the Tohono O’odham Nation and remains focused on open communication and minimizing impacts.” But the federal government, Jose said, has already “shown that it believes we’re only as sovereign as they allow us to be.”