Federal officials have paused a controversial construction project linked to President Donald Trump‘s southwest border wall through Big Bend National Park in Texas.

While federal officials did not plan to build a wall through the park, public lands advocates were outraged when contractors began bulldozing access roads through the area in early to mid-August. Videos recorded by activists captured bulldozers and track hoes cutting through the desert soil and across cliffs.

“Last night I put a pause on all activity in that park as far as construction goes until I can get down there and do a personal evaluation, talk to some stakeholders, talk to local law enforcement in that area,” Customs and Border Patrol Commissioner Rodney Scott said in an Aug. 17 video statement. “More to follow this week.”

Although very few illegal border-crossers currently try to cross the rugged landscape, federal officials said they needed roads to both install surveillance equipment and to permit routine patrol access in case migration patterns change. The Trump administration angered public lands groups in June by waiving environmental laws that would have otherwise slowed or prohibited that construction.

Trump campaigned on tough immigration enforcement and border controls, and he has made expansion of the border wall a key campaign promise. Environmental groups argued no wall was needed through Big Bend, a national park that was formally created in 1944 and spans about 801,000 acres of desert and mountains.

Local residents argue that the road construction itself is an environmental catastrophe. They staged an Aug. 12 protest against the project.

In a statement, the National Parks Conservation Association lauded the pause, but said significant damage has been done.

“Unfortunately, the federal contractors’ bulldozers have already inflicted tremendous damage to one of America’s most iconic national parks,” NPCA President and CEO Tiernan Sittenfeld said. “Their heavy equipment has torn through miles of priceless wild landscape, wreaking havoc on sensitive wildlife and irreplaceable habitat.  We demand that Customs and Border Protection take accountability for the destruction that has occurred at the park and do better by the American people and by our national parks.”

Congress last summer supercharged Trump’s border-security efforts with $46.5 billion in funding, and federal officials in June waived dozens of environmental regulations to speed up wall construction in or near the national park.

The park’s southern boundary forms about 118 miles of the U.S.-Mexico border, including along the Rio Grande. Protests against the border wall over the past several years have included some Trump voters, many local elected officials, environmental activists and migrant rights organizations.

On Aug. 13, as the bulldozers began their work, Scott in a statement to USA TODAY reiterated that workers were not building a wall. And he noted that it would be possible to both secure the border and limit work within the park.

“As we strengthen the border across the Southwest, we will not leave Big Bend as an opening for cartels to exploit by shifting their routes and tactics,” he said. “We are securing this park to protect its legacy – keeping it safe, secure, and pristine so American families can enjoy the beauty of our country, free from fear of cartel activity, for generations to come.”

Earlier in the year, the Trump administration indicated that it would skip building a physical barrier along about 372 miles of the border because of “unfavorable terrain or remoteness of location.” Other locations will receive vehicle bollards that will let wildlife pass through unimpeded, according to the Department of Homeland Security.

Speaking to reporters on Aug. 17, Texas Gov. Greg Abbott said he’s confident federal officials can both secure the park and the nation’s southern border. Abbot said he talked to Homeland Security Secretary Markwayne Mullin and received assurances there will be no wall or fence through the park. Abbot did not address the construction of access roads.

“They understand that there are other tools to successfully secure that park through technology, through personnel, through other means,” Abbot said. “There are technology tools that don’t include barriers.”