The National Park Service warns the push to get President Trump’s border wall built could destroy nearly two dozen archaeological sites in Arizona’s Organ Pipe Cactus National Monument.

In a 123-page report obtained by the Washington Post, the park service warns replacing the current 5-foot barrier with a 30-foot steel wall could severely damage yet-to-be excavated areas of the monument southwest of Phoenix that boasts the remnants of Sonoran Desert peoples. Damage also is caused by border agents in all-terrain vehicles pursuing migrants and smugglers, the Post reported.

Desert peoples have populated the area, which was part of a prehistoric trade route, for at least 16,000 years, especially near Quitobaquito Springs, which also is home to the Quitobaquito pupfish and Sonoyta mud turtle. At least a dozen Native American tribes still claim connections to the area.

“We’ve historically lived in this area from time immemorial,” Tohono O’odham Nation Chairman Ned Norris Jr. told the Post. “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.”

Desert wetlands are just 200 feet from the border and scientists fear the water could dry up if groundwater is pumped out to accommodate the barrier’s concrete base.

So far, construction has begun on a two-mile section of wall east of the border crossing at Lukeville, Arizona.

With Trump pushing to get 500 miles of wall built along the U.S.-Mexico border in time to use as a talking point ahead of the 2020 presidential election, U.S. Customs and Broder Protection has been fast-tracking construction since last month. The fence is part of a 43-mile span that also affects the adjacent Cabeza Prieta National Wildlife Refuge.

To speed construction, the Department of Homeland Security has been waiving federal requirements imposed by the Archeological Resources Protection Act, the National Historic Preservation Act and the Endangered Species Act. Trump has told subordinates not to worry about breaking laws, that he would pardon them if they ran afoul of environmental and other rules in getting the barrier done quickly.

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

Environment groups have tried to halt construction, saying the barrier could disrupt wildlife.

Border patrol says only five archaeological sites are within the 60-foot strip of land on the U.S. side of the border where the wall will stand. Construction plans in an area known to have remnants of stone tools and other artifacts have not yet been finalized.

 “Archaeology takes time, and they have a deadline,” Kevin Dahl, Arizona senior program manager for the National Parks Conservation Association, said, referring to border patrol. “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.”

Trump made building a wall along the border a feature of his 2016 campaign and has said the wall needs to be built so he can claim he kept his campaign promise. Chants of “Finish the wall” punctuate his rallies. During the first 2 1/2 years of his administration, the U.S. Army Corps of Engineers has finished just 60 miles of replacement barriers in areas that already had structures. Money for the wall is being diverted from Pentagon construction funds and other areas.