On moonless nights the Milky Way stands out like a stain across the sky of Organ Pipe Cactus National Monument. The monument is a 330,689-acre UNESCO biosphere reserve, and the only place in the United States where senita and organ pipe cacti naturally grow. 

The land on what is today known as Organ Pipe has been inhabited for thousands of years by the Tohono O’odham people and their ancestors, and is the site of the Quitobaquito sacred springs, a perennial spring-fed pool that has long served as waystation and site for O’odham ceremonies. It’s also the only home in the U.S. for the Quitobaquito Pupfish

Just a stone’s throw from the pool rise the rusting bollards of the border wall, which first went up, despite local resistance from the Tohono O’odham, in 2019. For miles in either direction, light poles sprout up as far as one can see.

Beginning in 2019, U.S. Customs and Border Protection began installing hundreds of the stadium-bright light fixtures along the border wall. There are now about 2,000 of them. The agency says the lighting will help with “domain awareness” for Border Patrol agents.

Border wall lighting infrastructure at Quitobaquito sacred springs at Organ Pipe Cactus National Monument. Russ McSpadden / Center for Biological Diversity

The lights have not been turned on yet but environmental advocates and Organ Pipe monument officials are worried about what will happen if they are. They are working to protect the pristine area from light pollution that experts say will flood the area with a glare as blinding as stadium lighting.

“Organ Pipe Cactus National Monument offers an incredible dark sky experience for visitors,” Scott Stonum, superintendent of the monument, wrote in a May 19 emailed statement. “The National Park Service and staff here highly value the park’s dark sky resources and have initiated the application process collecting the assessments and measurements needed for potential International Dark Sky Park certification.” The application process is modeled on other conservation programs, such as the UNESCO World Heritage Sites and Biosphere Reserves, and can take between one and three years.

How to get involved

• Read the report on the potential effects of the border lights from the Center for Biological Diversity.

• Read up on the International Dark-Sky Association and join the “dark sky movement.” You can also read further on the dark sky certification process.

• Visit or read about Organ Pipe Cactus National Monument.

• And learn more about Tohono O’odham history in and around the sacred Quitobaquito Springs

Such certification will be dead on arrival if the border wall lights are flicked on, polluting the night sky with hundreds of lights. 

In July of 2022, the Department of Homeland Security announced “remediation and mitigation” efforts they are planning in regard to existing border wall infrastructure. Those efforts include “installing updates – such as lighting, cameras, and detection technology – in places with a previously built barrier.” 

Stonum added that the National Park Service “provided comments at the request of CBP concerning potential impacts and suggested mitigations” as the first segments of wall were planned in 2019. “Concerns included potential impacts to natural and cultural resources: disturbance of archeological sites, disruption of wildlife corridors, wilderness values, scenic vistas, night-sky, and others,” he wrote.

Telescopes and astronomy centers abound in Arizona: there are 48 separate observatories around the state that need dark skies to operate. A 2012 ordinance from the city of Tucson required fully shielding outdoor municipal lighting and limits the total light produced at night. Flagstaff, Fountain Hills, Sedona and Cottonwood are certified dark sky communities and Southern Arizona parks and monuments with dark sky designation include the Chiricahua National Monument, Tumacácori National Historical Park, Kartchner Caverns State Park, and Oracle State Park.

Currently, areas along the U.S.-México border remain some of the darkest in the country, according to the International Dark-Sky Association, a Tucson-based organization that works on five continents to protect the night from light pollution. In 2022, a swathe of over nine million acres — from Fort Davis, Texas, to the Rio Grande River at the US-México border, including a number of protected areas in México – became the world’s largest and first bi-national International Dark Sky Reserve.

Mangled wires jut out of a light pole near the border in Arizona. Credit: John Washington

No such designation, or protections, exist for the dark nights along the border in Arizona, according to Ruskin Hartley, Chief Executive Officer and Executive Director at the Dark-Sky Association. And the thousands of unlit poles — some of them leaning sharply and in danger of toppling, many of them wire-gutted and needing obvious repair — currently standing like skinny crenellations following the border wall, threaten that darkness.

“Artificial lighting at night would be devastating to wildlife and conservation lands in Arizona along the U.S.-México border,” according to a report released June 6 by the  Center for Biological Diversity.

A light pole leans close to the border wall on Organ Pipe Cactus National Monument Credit: John Washington

In Organ Pipe Cactus National Monument alone, more than 270 bird species have been recorded, according to the center’s report. Artificial light has significant impacts on birds, which can be attracted to, repelled by or disoriented by lights.

Birds can crash into structures when they are thrown off by bright lights, and “many bird species use light cues in the environment for navigation, even using these cues to calibrate their sensitivity to the Earth’s magnetic field,” according to the report. “Artificial light interferes with this process.”

On the eastern side of the state, half of all breeding bird species in North America are known to use the San Pedro River corridor, according to the report. Currently, where the San Pedro River crosses the international border, there are 12 lights within a third-of-a-mile stretch. 

Bats are another animal that could be negatively impacted by switching on the border wall lights. They are nocturnal, and play important roles in maintaining a functioning ecosystem in each of conservation areas where the Center for Biological Diversity surveyed border lights. 

Hartley called the Southern Arizona deserts “some of the most remote and some of the darkest places that remain in North America.” 

These are “places that are still a long way away from any sources of light pollution,” Hartley said.

“Our organization is not opposed to lighting,” Hartley said. “But when our board looked at it, we said, ‘Look, these are very dark, remote locations. We have talked to some in law enforcement and people working there and these super bright lights and these very dark locations will actually not do much from a deterrence perspective.” 

A light pole towers over everything along the border in Arizona’s Organ Pipe Cactus National Monument. Credit: John Washington

CBP did not respond to repeated questions about the lights’ deterrence effect.


On June 8, two days after this story published, a U.S. Customs and Border Protection spokesperson responded via email to questions — about lights installed along the border wall —originally submitted by Arizona Luminaria on April 21.

“Currently, CBP is evaluating the priority areas for powering on lights. CBP is including biologically sensitive areas and Federal lands that employ night sky initiatives in its evaluation.”

In response to questions about whether the agency has conducted an environmental impact study regarding the lights, CBP stated:

“In areas where barrier was constructed between 2017 and 2021, CBP will conduct a review of environmental impacts pursuant to the National Environmental Policy Act (NEPA) to install new lights where none exist and/or power on lights where lighting infrastructure had been installed. Through the NEPA process, CBP will evaluate the potential for environmental impacts and obtain feedback from the public and other stakeholders on lighting.”

CBP added that, “On July 11, 2022, DHS announced an Amendment to the Plan which allows CBP to prioritize remaining prior year border barrier funding to install system attributes, to include, as appropriate to the area, cameras, detection technology, and lighting, in areas where barrier was already constructed. This supports CBP and DHS’s priority to continue to deploy modern, effective border measures and improve safety and security along the Southwest Border.”

CBP did not comment on how many lights there are, where they are located, how much they cost, or when they might turn them on.

In May, Arizona Luminaria contacted DHS and the U.S. Army Corps of Engineers to inquire about the extent of and plans for the lighting systems. Both agencies recommended reaching out to CBP. Despite repeated requests in May and early June for information from CBP, the agency did not respond to detailed questions about how many lights there are, how much they cost, how bright they will be, what environmental studies they’ve conducted about the lights or when, if ever, they might turn them on.

“Keeping the lights off is not going to save the wildlife in the area because there’s already a physical barrier” that has threatened them, Hartley said. Turning the lights on, however, “just adds to the impact.”

“If the lights were energized, if they were turned on, the impact in these very dark places could be seen for dozens and dozens of kilometers,” he said. 

Hartley estimated that the lights were between 50,000 and 150,000 lumens, “which is equivalent to stadium lights.”

Russ McSpadden is a southwest conservation advocate for the Center for Biological Diversity. He recently spent a few weeks counting the lights, finding hundreds of them on the Organ Pipe Cactus National Monument, the Cabeza Prieta National Wildlife Refuge, the San Pedro River National Conservation Area, and the San Bernardino National Wildlife Refuge. Those protected places are habitat for at least 16 threatened and endangered species, including the yellow-billed cuckoo, Quitobaquito pupfish, Sonoyta mud turtle, beautiful shiner, Yaqui catfish, Yaqui chub and San Bernardino spring snail.

A concrete pylon anchors a light pole next to a saguaro cactus close to the border wall. Credit: John Washington

While the effect of lights on fish may not be as obviously apparent, Krista Kemppinen, the Center for Biological Diversity’s senior scientist says that like many animals, “fish possess light detecting cells involved with making sure their biological clock is synchronized.” 

“Fish use light to dictate their behavior, from regulating rest, foraging, and other daily patterns,” Kemppinen added. 

She said a disruption in how they regulate their activities by light pollution could “lead them to expend more energy on some activities and, for example, affect their habitat preferences or mating cycles.” 

While she was not aware of any specific studies about light and the Quitobaquito pupfish, she said, “Some fish will use the moon cycles to determine when to lay their eggs” — noting that following that natural light cycle could be much harder with nearby bright lights.

The Center for Biological Diversity sent CBP a letter on June 6, demanding, among other things, that the agency, “remove and prevent new lights and lighting infrastructure within national wildlife refuges, monuments, and conservation areas that are relatively free of artificial lighting at night.”

Credit: Center for Biological Diversity

If they’re not willing to remove the lights, the center urges CBP to conduct a National Environmental Policy Act review of the “direct, indirect and cumulative effects” of the lights.

According to the Dark-Sky Association and the Center for Biological Diversity, no such study has been conducted. CBP did not respond to questions sent repeatedly in May and early June about environmental reviews.

The center’s letter also encourages CBP to “work with the public, local communities, and federal land managers and biologists” at the monument and various refuges “to better understand the impacts of lighting on those protected areas’ wildlife, ecosystems, tourism and nearby communities.”

Driving along the border wall road, stopping every 175 feet or so to mark the GPS coordinate of each light pole, McSpadden asks, “What do we lose when we lose the darkness?”

According to a 2022 study from the Royal Society, one specific and beloved bug – the endangered Southwest spring firefly – stands to lose: Artificial light pollution interferes with courtship displays, disorients the glowing insects, and effectively blinds them by saturating their “dark-adapted compound eyes.”

“Artificial light is particularly disruptive to fireflies, charismatic beetles that have attracted popular and scientific interest for millennia,” the study notes. And while that may seem to be a small effect, there are potentially “cascading consequences for ecological communities.”

Those cascading effects may be felt across ecological communities along the Arizona border and sovereign tribal lands if CBP turns the lights on.


Visuals: John Washington and Russ McSpadden/Center for Biological Diversity Editor: Irene McKisson Copy Editor: Dianna M. Náñez

Creative Commons License

Republish our articles for free, online or in print.

John Washington is an investigative journalist based in Tucson with a focus on immigration and borders, as well as criminal justice and literature. His first book, "The Dispossessed: A Story of Asylum...