For the past seven weeks, the state of Arizona has been constructing a makeshift barrier on its southern border by lining up hundreds of shipping containers to deter illegal immigration.
The project has alarmed ecologists, flummoxed lawyers, and mobilized a group of protesters who are trying to stop it. This barrier will block wildlife movement in a biologically diverse region, and its unapproved construction is damaging Forest Service land, knocking over trees, and causing significant soil erosion.
Beginning in late October, Governor Doug Ducey ordered the barrier to be built along 10 miles of the border abutting the Coronado National Forest in a remote wilderness area 70 miles southeast of Tucson. Workers have already put up 3.5 miles of double-stacked shipping containers, topped with razor wire. Each container measures 40 feet long, more than eight feet tall, and weighs 8,000 pounds.
The barrier of containers cuts through the Huachuca Mountains and the grasslands of San Rafael Valley, which together make up one of the richest and most important conservation lands in Southeastern Arizona’s borderlands. Intended to block migrants, the barrier will also block critical wildlife corridors for diverse populations of animals, including endangered jaguars and ocelots, along with mountain lions, black bears, coati, mule deer, and javelinas.
“These animals need to be able to move to survive,” says Emily Burns, a conservation biologist and program director with the Sky Island Alliance, a conservation group. “Even the smallest animals will not be passing through.”
Legally, matters involving international borders fall to the federal government, not states. But the U.S. Forest Service, a primary agency that would oversee such a project—since this section of border abuts Coronado National Forest—did not authorize the unsanctioned work. The project runs afoul of several major federal laws, such as the Endangered Species Act, Burns says. (Related: Arizona’s border wall will include openings too small for many animals.)
Upon beginning the work, Ducey filed a lawsuit against the federal government, claiming he had the authority to act unilaterally due to what he called a “crisis” posed by illegal immigration. Ducey said in a news release that more 230,000 migrants crossed the Arizona-Mexico border illegally from October 2021 to August 2022—although large numbers of these migrants cross to seek asylum protections, for which they plan to be apprehended by Customs and Border Protection officers and appear in court.
“The goal is to make it more difficult to enter the United States illegally,” says C.J. Karamargin, communications director for Ducey. When asked about violating federal laws, he referred to the lawsuit Ducey filed, and emphasized that the governor is primarily concerned with “public safety and illegal immigration,” not environmental issues.
The Forest Service did not respond to questions and instead referred National Geographic to the Department of Justice, which doesn’t comment on ongoing litigation. However, in a November 23 filing, the DOJ asked the Arizona District Court to dismiss Ducey’s case, calling the state’s actions “unlawful” and saying the governor’s “claims have no basis in fact and law.”
A small group of protesters have flocked to the region to stand in front of the contractors’ equipment and prevent them from carrying on destructive work. This nonviolent approach, in which protesters are risking their safety, has so far halted the construction on at least seven different days, says Russ McSpadden, with the Center for Biological Diversity, a group that has sued the state of Arizona to halt the construction. McSpadden is recording much of what he observes and shares it on his Twitter account. In the last few days work crews have shifted their activity to late evening to avoid interruption, so protesters are camping out near the area in response, and halted the construction around 3 a.m. today, December 7.
Southeastern Arizona and the Mexican state of Sonora is home to the Sky Islands, mountain chains that connect subtropical ecosystems with temperate grasslands and forests to the north. It is one of the most biodiverse regions in the United States, home to animal and plant species found nowhere else in the country, including ridge-nosed rattlesnakes, elegant trogons, and Tarahumara salamanders.
The Huachuca Mountains are also one of only two U.S. ranges home to four cat species: mountain lions, bobcats, jaguars, and ocelots. This area is thought to be where a famous jaguar, known as El Jefe, passed into the United States, roaming the wild of the Santa Rita mountains near Tucson from 2011 to 2015. He also likely exited here to return to Mexico, and, incredibly, was rediscovered by a camera trap in central Sonora earlier this year. One reason this area is such an important corridor is because of its high elevation and high-quality habitat of oak savannah, says Michael Bogan, a University of Arizona biologist.
Cross-border wildlife movement is vital to the ecological health of the Southwest and beyond, says Myles Traphagen, a biologist with Wildlands Network, a conservation group. He says that such barriers threaten to impair the “evolutionary history of North America.”
Another conservation group, the Sky Island Alliance, has been running a camera trap study along the border, including parts of the San Rafael Valley and the Huachucas. The group has captured images of more than 20 mammal species within the Huachucas, with some camera traps less than a mile from where new barrier is going up. Many of these are flagship species in the region, including gray foxes, ringtails, antelope jackrabbits, and four types of skunks. (See also: An endangered wolf went in search of a mate. The border wall blocked him.)
The west side of the Huachucas drains into the Santa Cruz River, a crucial source of water for towns including Nogales and Tucson. Animals that live here could be harmed by runoff from the construction work, Bogan says. He also worries that even if the shipping containers are removed, erosion caused by the workers’ widening of roads and earth movement could last for years, and mitigation work might prove difficult to fund.
Ducey’s container barrier is not the first to be ordered urgently by a politician warning of a migrant crisis. From 2018 to 2020, the Trump Administration built more than 225 miles of fence along the Arizona-Mexico border, most of it 30 feet tall that replaced shorter barriers. Unwalled stretches remain along the Arizona border, many of them remote and mountainous, such as the Huachucas.
The wall in the Huachucas is a continuation of a tactic the governor started this summer, which involved using shipping containers to plug gaps in existing fencing outside Yuma, an agricultural area frequently used for border crossings.
The vast majority of the Trump-era barrier was built abutting federal land. Traphagen, the biologist, says the Trump wall has changed the look and ecological functioning of the landscape in negative ways. In addition to blocking wildlife corridors, building the structure required enormous amounts of scarce groundwater—up to 700,000 gallons per mile in some areas—for the structure’s cement base. (Learn more: Sacred Arizona spring drying up as border wall construction continues.)
McSpadden, with the Center for Biological Diversity, is not alone in wondering why the Forest Service has not moved to stop the work. “Nobody can just go into a national forest and rip out trees and drive heavy equipment through the grasslands,” he says. He has documented workers grading roads and pushing sediment into washes, tearing up ground cover, and knocking over around 30 oak trees.
For now, the project has a deadline. Ducey, a Republican, leaves office on January 2 and will be replaced by governor-elect Katie Hobbs, a Democrat, who is not expected to continue the project.
However the conflict resolves, wildlife will continue to be blocked by fencing in other areas. Beginning in November the Biden administration began preparing to fill gaps in several sections of the Trump-era border wall within the Pajarito Mountains, a wilderness area also home to many rare species of plants and animals. The area is also one of the state’s primary jaguar corridors, and designated as critical habitat for this endangered species.