Big Bend region named world’s first International Dark Sky Reserve

A map of the Greater Big Bend Dark Sky Reserve Map, which now includes areas of Chihuahua and Coahuila.

TRI-COUNTY — Last week, the McDonald Observatory announced that the greater Big Bend region — which includes protected areas across the border in Mexico — had become the world’s first International Dark Sky Reserve. The new designation not only marks Big Bend as the first such binational reserve, but at more than 15,000 square miles, it has also become the world’s biggest.

The designation comes courtesy of the International Dark Sky Association (IDA), “the leading organization combating light pollution worldwide,” per their website. Both the state and national Big Bend parks have long enjoyed IDA status in support of a larger Big Bend reserve protecting the night sky around the McDonald Observatory. 

The region has always been ahead of the curve when it comes to dark sky protections. The first lighting ordinances in the area date back to the 1970s, when a group of astronomers at the observatory got together to create local ordinances for the town of Fort Davis to protect the night sky in the Davis Mountains. 

“The observatory has been promoting dark skies for decades,” said Ashley Wilson, director of conservation for the IDA. “That’s not something we normally see — most of the time, we see places recognize a light pollution problem and then retroactively try to make amends.” 

Wilson explained that dark sky reserves typically have a “core,” or an area most in need of protection, surrounded by a “periphery.” The Big Bend reserve’s core is located around the McDonald Observatory, on land owned by the Nature Conservancy and the University of Texas. The “periphery” includes all of the tri-county area and Balmorhea, as well as the Parque Nacional de Santa Elena in Chihuahua and the Ocampo and Maderas del Carmen Áreas Protegidas in Coahuila. 

The goal of establishing the core almost 50 years ago was to protect the work of the McDonald Observatory, which depends on a clear view of the night sky. “From the observatory’s standpoint, we want to protect the skies to ensure our research can be successful,” said Stephen Hummel, dark skies specialist at the McDonald Observatory. 

The facility’s powerful Hobby-Eberley telescope is currently hard at work mapping the universe and investigating “dark energy,” a force that causes the universe to expand faster as it ages. While the observatory’s current projects sound like something out of a sci-fi novel, Hummel said the research will have a ripple effect in shaping the way we understand ourselves. 

“In terms of everyday life, I think if we lose our connection with the night sky, I think we lose a little bit of our humanity,” Hummel said. “Astronomy is, in a sense, the oldest science. Since people have had eyes to look up with, they’ve been connecting with the nighttime.” 

While the observatory’s hometown community of Fort Davis led the dark sky protection charge years ago, other communities have followed suit after seeing all of the benefits, including protections for wildlife and opportunities to cash in on tourism. 

“There’s a huge contingency of people who have been coming out here to see the sky for a long time,” said Laura Gold, member of the Alpine Night Sky Team, an organization that has banded together in North Brewster County to help their neighbors switch to dark sky-friendly lighting. “Some people come out here generation after generation because it’s the only place they’ve ever seen the night sky. The sky is part of the landscape here.” 

Hummel agreed that there was much more to protecting the local night sky than providing the perfect canvas for the observatory’s telescopes. “Something like 80 percent of Americans can no longer see the Milky Way,” he said. “I think there’s an important cultural aspect to preserving the night sky.”

Beyond the cottage industries that have cropped up in the Big Bend around astro-tourism and astrophotography, keeping our dark skies dark could protect a higher quality of life for locals, both animal and human. Darker skies can regulate circadian rhythms and protect migration patterns and routes. 

“Light pollution is a really serious health issue, not just for people, but for wildlife,” Gold continued. “There’s a learning opportunity here to study the effects of darkness. People don’t understand what darkness means; most people are just afraid of it. But it’s an important part of our health to have a dark night. Different kinds of light affect you differently and there’s a lot of science to support that.” 

Across the border in Chihuahua and Coahuila, local officials have been having the same conversations. The Comisión Nacional de Áreas Naturales Protegidas (CONANP), Mexico’s version of the National Park Service, began negotiations with the entities involved in the American Big Bend Dark Sky Reserve around two years ago. 

“It became clear that the values of CONANP are very closely aligned with the values here. Dark skies are important for not just astronomical research or tourism, but they’re also important for wildlife. So from that angle, the conclusion was clear on both sides: dark skies are mutually beneficial,” Hummel said. 

Prior to the Big Bend Reserve’s designation, the only recognized IDA site to span an international border was the Waterton-Glacier International Peace Park on the U.S.-Canada border. Waterton-Glacier is classified by the IDA as a “dark sky park,” formed by a single organization, whereas the Big Bend is home to a “dark sky reserve” that includes parks, communities, and other entities. “It’s really a hybrid,” Wilson explained. “The Big Bend reserve is a milestone because it’s the first of its kind.” 

“I think it will be unique in that way for a while,” she continued. “Most of the applicants for reserves that I’m working with are within a single country or even a single state. I think having this conversation with people in different countries and especially with different languages makes this effort that much more complicated — not to say that it can’t be done.” 

Officials from the city of Ojinaga, which is not currently included in the reserve’s boundaries, were originally included in negotiations, but the language barrier and numerous complications at the borders due to COVID made those conversations much more difficult. Ojinaga switched its city streetlights to dark sky-friendlier LEDs back in 2015, but as the biggest community in the greater Big Bend region, there’s still a lot of work to be done. 

“The reserve wants to commit to help a community like Ojinaga and answer their questions and help them pick out quality lighting,” Wilson said. “We want to make it a mutually beneficial relationship from the beginning, so we can continue to grow and protect more dark skies across both sides of the river.” 

For Gold, who’s lived in practically every corner of Brewster County over the past 20 years, the fact that both countries have come together to protect the night sky speaks to what makes the Big Bend special. 

“The sky doesn’t stop at the border, it doesn’t stop at the county line, it doesn’t stop at the edge of town,” she said. “It’s not my sky, it’s not your sky — it’s our sky.”