When Lisa Manuel was a child, her mother would take her to Quitobaquito Springs, a rare oasis amid the giant cacti and rolling hills of southwest Arizona’s Sonoran Desert. For at least 10,000 years, the spring has been a vital source of water for wildlife and people, including the Tohono O’odham and Hia-Ced O’odham, whose ancestral territory spans the U.S.-Mexico border. “It’s been a part of my family all my life,” says Manuel, a descendant from the Hia-Ced O’odham. “It’s a beautiful place. It’s a sacred place. I sit there and I pray.” For months Manuel and others have fought to defend this ancient haven, which they fear is being destroyed by construction of President Donald Trump’s signature border wall just 200 feet from a pond the spring feeds. Since August 2019, crews installing a 30-foot-high wall in Organ Pipe Cactus National Monument have blasted sacred sites near Quitobaquito and used up to 3 million gallons of groundwater per month to mix...