Big Bend National Park, Texas —

The towering cliffs, jagged mountain tops, and punishing desert climate of the Big Bend region in Texas have long proved to be the best barrier the United States could have with Mexico. For generations, the idea of needing to build physical structures to stop illegal migration was considered “insane,” as one former superintendent of Big Bend National Park said.

But now the expansive reach of President Donald Trump’s southern border plan has stretched into this remote region that sees only about 1% of unauthorized crossing apprehensions. Bulldozers are clearing land in the beloved national park, where wildlife roams and the scenery has been untouched for thousands of years.

“We didn’t have to worry about any type of barrier. We had a God-made barrier,” said Sheriff Thaddeus Cleveland of Terrell County, a vast and sparsely populated area northeast of the park. He spent 26 years in the US Border Patrol, hearing little if any talk of needing extra infrastructure in the area where he grew up, he said. “But that’s definitely changed.”

US Customs and Border Protection says it’s not planning to build the same kind of 30-foot-high barrier that has appeared across parts of Arizona, California, New Mexico and Texas inside the national park. But critics say the plan that is in the works is no less destructive.