Terlingua, Texas, and surrounding communities in the Big Bend region are bracing for potential impacts to their famously dark night skies due to the planned construction of a border wall along the U.S.-Mexico boundary. Residents and dark sky advocates warn that lighting associated with the wall could significantly disrupt the area's natural nighttime environment, which has long been a defining feature of the region.

The border wall project, promoted during the Trump administration, includes plans for roughly 165 miles of barrier in the Big Bend area, according to the latest map from U.S. Customs and Border Protection (CBP). While the agency states that lighting will be used selectively and primarily based on operational needs, concerns remain that even limited illumination could jeopardize the region’s dark sky status and affect local ecosystems, scientific observation, and tourism.

Advocates say the current darkness is integral not only to preserving the rural character of Big Bend but also to supporting local economies that have developed around stargazing and astronomy. Big Bend National Park was designated the region’s first certified dark sky site in 2012, and since 2022 the area, stretching across nine million acres on both sides of the border, has been recognized as the world’s largest dark sky reserve.

Lighting already installed along other border wall segments in Arizona and eastern Texas serves as a cautionary example. “That technology is there, and it is literally a flip of a switch away,” said Billy Bartko, director of Terlingua’s Far Flung Outdoor Center. He and other residents worry that illumination could rapidly spread, erasing the dark skies they have fought to protect.

Experts note that artificial light could interfere with the research conducted at McDonald Observatory, located hundreds of miles away but sensitive to increased brightness. For others, the concern is cultural and environmental — that widespread lighting signals increased development and threatens the region’s natural tranquility. David Keller, an archaeologist and Big Bend historian leading a coalition opposing the wall, said dark skies represent the core reason many residents chose the area.

The region has seen a growing interest in astrophotography and stargazing-related tourism. Activities such as workshops, star parties, and remote telescope shipping have become part of the local economy, with stargazing ranked as the second most popular tourist activity in a 2022 survey. Some residents fear that border wall lighting and associated infrastructure—including temporary worker housing, road construction, and surveillance installations—could disrupt these businesses and alter the region’s appeal.

CBP said that in more remote stretches, lighting would be minimized in favor of alternative surveillance technologies like infrared sensors. The agency’s map indicates reliance on detection equipment and patrol roads, rather than physical barriers, near some sensitive areas such as Big Bend Ranch State Park and sections adjacent to Terlingua.

Still, the area's open, flat terrain allows light to travel far, and small cities up to 50 miles away already generate noticeable glow on clear nights. Preparations for wall construction began near Presidio in June, and local residents have reported lighting that does not comply with established dark sky practices.

Advocates emphasize that the concern extends beyond the wall structure itself. “It’s not just the lighting associated with the wall, it’s the lighting associated with all the auxiliary things that are going to be coming with it,” said Amber Harrison, a local leader in dark sky conservation.

Many Big Bend residents, including some who supported former President Trump, have rallied against the wall, driven by a shared desire to preserve the region’s natural beauty and way of life. For those who cherish the ability to look up and see the Milky Way, the prospect of losing that view is deeply personal.

“Being able to look up and see the Milky Way, it just kind of shifted my life,” said Valerie Stanley, who moved to Terlingua in 2020. “Now I’m living a different life with all this beauty that I never really knew was here.”