Before the Trump administration decided the country urgently needed to erect a hulking steel wall in southern New Mexico’s Bootheel, only a three-strand barbed wire fence separated the United States from Mexico in this arid stretch of the Chihuahuan Desert.

“Maybe I’d see a Border Patrol truck, a rancher and a couple of cows,” said Teresa Martinez, co-founder and executive director of the Continental Divide Trail Coalition, a national nonprofit that helps steward the trail. Now, she said, it’s a “construction zone.”

Almost exactly a year ago, Secretary of the Interior Doug Burgum transferred 110,000 acres of federal land from the Bureau of Land Management in New Mexico into the jurisdiction of the U.S. Army. The emergency measure, he said, was spurred by a need “to secure the border and protect the nation’s resources.”