Unlike concerns about the barrier project that have come from private landowners, churches, communities and advocacy groups, these new warnings about the potential destruction of historic sites come from within the government itself.

The National Park Service’s 123-page report, obtained via the Freedom of Information Act, emerges from a well-respected agency within the Interior Department as the Department of Homeland Security and the White House push ahead with their construction plans. While the government scrambles to analyze vulnerable sites as heavy equipment moves in, the administration also faces external challenges seeking to block the use of eminent domain to seize land, as well as lawsuits asking courts to halt work in and around wildlife refuges and other protected lands.

New construction began last month within the Organ Pipe Cactus National Monument, an internationally recognized biosphere reserve southwest of Phoenix with nearly 330,000 acres of congressionally designated wilderness. The work is part of a 43-mile span of fencing that also traverses the adjacent Cabeza Prieta National Wildlife Refuge.

With the president demanding weekly updates on construction progress and tweeting out drone footage of new fencing through the desert, administration officials have said they are under extraordinary pressure to meet Trump’s construction goals.

The Department of Homeland Security has taken advantage of a 2005 law to waive several federal requirements — including the Archaeological Resources Protection Act, the National Historic Preservation Act and the Endangered Species Act — that could have slowed and possibly stopped the barrier’s advance in the stretch in Arizona.

Watch more!

Some archaeological features along the border already have suffered damage as Border Patrol agents zoom through in pursuit of migrants and smugglers in all-terrain vehicles, according to federal officials and two experts who have conducted research in the region.

Environmental groups have fought unsuccessfully to halt construction in protected areas, arguing that more-imposing barriers could disrupt wildlife migration and threaten the survival of imperiled species.

But there has been little mention of the potential damage to archaeological sites, where stone tools, ceramic shards and other pre-Columbian artifacts are extremely well-preserved in the arid environment. Desert-dwelling peoples have populated the area for at least 16,000 years, particularly around the oasis of Quitobaquito Springs in the national monument, one of the few places where the Quitobaquito pupfish and the endangered Sonoyta mud turtle still live in the wild.

The oasis was part of a prehistoric trade route, the Old Salt Trail, where northern Mexican commodities including salt, obsidian and seashells were plentiful, according to the Park Service. The traders were followed by Spanish missionaries, Western settlers, and other travelers and nomads who came to drink.

A cactus is silhouetted at Organ Pipe Cactus National Monument near Lukeville, Ariz., and the U.S.-Mexico border. (Jim Watson/AFP/Getty Images)

The springs and surrounding desert wetlands are just 200 feet from the border, where crews plan to bring in heavy earth-moving equipment to install the giant steel barriers. Scientists have raised concerns that the springs could dry up if crews pump groundwater from the area for the barrier’s concrete base.

CBP officials said the agency has looked at “most” of the archaeological sites identified in the Park Service report and found just five that are within the 60-foot-wide strip of federal land on the U.S. side of the border where the government will erect the structure, an area known as the Roosevelt Reservation, which was set aside along the border in California, Arizona and New Mexico. Of those five, officials said, one had a “lithic scatter” — remnants of stone tools and other culturally relevant artifacts.

Construction crews do not yet have a plan to begin work at that location, CBP officials said, noting that the agency has had discussions with the Park Service about collecting and analyzing fragments of historic significance from that site.

“We’ve been working very closely with the park,” said a CBP official, who spoke on the condition of anonymity to discuss the administration’s plan for building near archaeological sites along the border.

The officials said they have not delayed or otherwise altered their construction plans to conduct more detailed surveys or excavations in the area.

Officials said crews with earth-moving equipment have started installing barriers in a two-mile section east of the border crossing at Lukeville, Ariz., a particularly busy stretch for illegal crossings.

CBP officials acknowledged that trucks and earth-moving equipment driving through the fragile desert risk harming sites outside the specific construction zones. The officials said they are following Park Service guidance as to where workers can drive.

This photo shows why a border wall won’t stop immigration surge By undefined, undefined, undefined, undefined and undefined President Trump has declared an emergency at the border. This photo shows why a wall won’t stop asylum seekers from flooding into the United States.

With CBP, the U.S. Army Corps of Engineers and their construction contractors under pressure from the White House, federal land in the West has become the easiest place to quickly add fencing. There are few private landowners in the desert terrain outside Texas, and it is a far easier place to build than along the winding riverbanks of the Rio Grande.

At least a dozen Native American tribes claim connections to the lands within the Organ Pipe Cactus National Monument, especially near Quitobaquito. They include the Tohono O’odham Nation, which used to inhabit a large swath of the Sonoran Desert and whose reservation lies north and east of the park’s boundaries. Members of the nation — who have revived the practice of following the Old Salt Trail — have protested the idea of any new construction in an area once inhabited by their ancestors, the Hohokam, who lived there between 200 and 1,400 A.D.

Tohono O’odham Nation Chairman Ned Norris Jr. said his tribe remains opposed to any new border fence construction.

“We’ve historically lived in this area from time immemorial,” he said. “We feel very strongly that this particular wall will desecrate this area forever. I would compare it to building a wall over your parents’ graveyards. It would have the same effect.”

Rick Martynec, an archaeologist who is conducting volunteer surveys of sites within the Cabeza Prieta National Wildlife Refuge along with his wife, Sandy, said researchers have not had time to properly evaluate the area now targeted for construction.

“Quitobaquito, as we know it, may be destroyed before anyone has had a chance to evaluate the consequences of the current actions,” Martynec said. “What’s the rush?”

He noted that relevant sites within the monument “include evidence of hunting, farming and home sites” along with “historic cemeteries.” He added that the adjacent wildlife refuge has other archaeological artifacts, including a rare intaglio figure spanning several hundred yards that was probably created for a ritual.

Watch more!

The Martynecs were doing research in the refuge at one point and saw a Border Patrol agent on a four-wheeler motoring up a road on which the agency was not authorized to drive, “right over a huge roasting pit” used by an ancient community, he recalled. They later checked to see if an incident report had been filed — as would be required if the agency was traversing that land — but none had been, Martynec said.

In the Park Service report summarizing the results of a survey of 11.3 miles along the U.S.-Mexico border, the agency’s archaeologists note that previous research had “identified and recorded 17 archaeological sites which likely will be wholly or partially destroyed by forthcoming border fence construction.” The park experts, who conducted their survey in June, identified five more archaeological sites that also would be imperiled and would deserve to be protected by a National Register of Historic Places designation.

The report notes that staffers were unable to complete a survey of the entire length of the U.S. side of the border that lies within the monument’s boundaries. Park Service archaeologists plan to survey another 1.7-mile section of the park’s southern border later this month.

Kevin Dahl, Arizona senior program manager for the National Parks Conservation Association, said that under normal circumstances, the agency would take steps to protect archaeological sites under its purview, including a lengthy excavation process if necessary.

CBP has announced plans to complete this section of barriers through the national monument by January. Those plans call for new fencing in five or six “non-contiguous areas,” including places within the monument where the archaeological sites are found, agency officials said. The sections of new barrier are not necessarily contiguous because the terrain might be too steep or mountainous to install a single, unbroken span of fencing.

The project within the monument includes a new steel bollard fence running continuously for 9.1 miles, reinforced with an 8- to 10-foot-deep concrete-and-steel foundation.

“Archaeology takes time, and they have a deadline,” Dahl said, referring to CBP. “Putting a wall there is insane. This is just one more reason why ramming this wall through, using illegal, unconstitutional money, is damaging to these public resources. We’re destroying what the wall is supposed to protect.”

A section of the border barrier runs uphill through Organ Pipe National Monument, behind a park warning sign in Lukeville, Ariz. (Matt York/AP)

National Park Service spokesman Jeremy Barnum said the agency’s mission “is to preserve unimpaired the natural and cultural resources and values of the National Park System for the enjoyment, education, and inspiration of this and future generations.” But he noted that some of the parks along the U.S.-Mexico border have been subjected to “cross-border illegal activities” and that the agency has coordinated with the Department of Homeland Security to address the issue.

In 2002, a park ranger at Organ Pipe was shot and killed as he pursued members of a drug cartel hit squad who had fled to the United States from Mexico. The Park Service closed more than half the monument to the public the following year but reopened it entirely in September 2014.

“The National Park Service appreciates the role of an integrated border security approach and values the ongoing interagency efforts to address the multidimensional issue,” Barnum said.

An archaeologist working for a CBP contractor, Northland Research, is on site every day when crews are working on the barrier fence, according to federal and tribal officials. The firm referred requests for comment to the government agency.