In the latest sad litany of pro-extraction industry decisions handed down by the federal government, the U.S. Forest Service said Friday that the Doe Run Company should be allowed to drill up to 232 holes in Missouri’s Mark Twain National Forest to search for possible lead mining sites. About 80 percent of the nation’s lead comes from Missouri, and all of that comes from a single rich vein that runs beneath the trees and rivers of the Ozarks. Drilling advocates say lead mining is essential for the region’s economy, but critics point to an ever-increasing number of drilling permits in the nation’s remaining pristine areas, and, in the specific case of Mark Twain National Forest, worry that the porous limestone in the area could allow pollution from drilling to reach distant watersheds. A final decision on permits for the company will be made by the Bureau of Land Management.