As the flood of foreign aid that has buoyed Afghanistan's economy for more than a decade recedes, the country's prosperity may well depend on its prodigious mineral resources, valued at $908 billion. The U.S. Geological Survey has been putting scientific boots on the ground to acquire more data that will help mining companies decide whether to invest in Afghanistan. As Science went to press, the final scoping mission was about to get under way to probe a potential reserve of lithium. A major impediment to developing Afghanistan's reserves was removed last month, when parliament passed the country's first mining law. But Afghanistan faces huge challenges in shifting to a minerals-based economy. It lacks roads, railroads, and electrical lines—and is also short of energy and water. Another formidable challenge is security.