A border-wall construction project damaged part of an ancient, fish-shaped earthwork in southern Arizona that the Tohono O’odham Nation regards as sacred, according to archaeologists and conservation advocates. The damage occurred April 23, when a U.S. Customs and Border Protection contractor drove heavy equipment through the Cabeza Prieta National Wildlife Refuge, the Center for Biological Diversity said. The group documented a scraped corridor about 50 feet wide cutting through the Las Playas Intaglio, a geoglyph roughly 272 feet long. An intaglio is made by clearing dark stones from the desert surface to expose lighter soil beneath. The Las Playas figure lies within the ancestral homelands of the Tohono O’odham, Hia-Ced O’odham and other Indigenous peoples. The scale of the damage has taken on added significance following new age estimates. Researchers writing in the Society for American Archaeology’s journal Archaeological Record report that the geoglyph is at least 6,500 years old, rather than roughly 1,000 years old as previously believed. The finding makes it the oldest scientifically dated geoglyph in the Americas, according to the report. The researchers examined stones collected from the site in 1979 using varnish microlamination dating, a method that compares microscopic layers of rock varnish with records of past regional climate. Three samples supported an age estimate of 6,500 to 7,300 years. Because the varnish formed after the earthwork was made, the figure could be older, said Russ McSpadden, the Center for Biological Diversity’s Southwest conservation advocate. The estimate places the site’s creation about 2,000 years before construction of Egypt’s first pyramid and about 1,500 years before Stonehenge was first built. “This discovery makes an already devastating loss even more profound. It’s a cultural and historical atrocity,” McSpadden said. Researchers describe intaglios as important to Indigenous cultural and religious traditions, tribal identity and continuing connections to ancestral lands. McSpadden urged Congress to seek records and testimony identifying who authorized the work, what warnings were issued and why any safeguards failed. The Center called the damage a loss to Indigenous communities and the public. The account provided no response from Customs and Border Protection or the contractor.