TULSA — Picher-Cardin Schools will graduate a final class of 11 next month, as the last residents leave an area of northeastern Oklahoma ravaged by decades of lead and zinc mining and a deadly tornado. There are only 49 students left in grades three through 12, whittled from several hundred a few years ago. In the past three years, the school cut athletics, band and art programs. "It's time for students to become involved in schools that have activities and can offer classes we don't offer now," Superintendent Don Barr said Friday. Earlier this month, the residents who were left decided to dissolve the Picher-Cardin district by a vote of 55-6, which means the remaining students will attend school next year in the nearby Commerce or Quapaw school districts. Undercut with mine shafts and buried under bleak, gray mountains of lead waste, Picher lies in the middle of the Tar Creek Superfund site, a 40-square-mile area that became one of the nation's worst environmental nightmares. For decades, before Picher became a town, miners carved miles of tunnels under its land, and the bounty of lead ore they recovered made bullets for both world wars. Neighboring communities were also undercut. During its boom, Picher's population peaked at 20,000. Saloons and movie parlors lined the streets. But the mines closed around 1970, and the town never fully recovered. In the 1990s, a study found elevated blood lead levels in Tar Creek-area children, and teachers began noticing years ago that students were learning more slowly and couldn't focus. In 2006, a U.S. Army Corps of Engineers study found more than 100 homes in Picher were in danger of collapsing into old mines. Last spring, just weeks after residents gathered to mark the town's final days with a parade, a massive tornado tore through the area, killing six people. A federal buyout has hastened the town's closure. For Barr, next month's graduation will be bittersweet, as the school that was once the focus of the small community closes its doors for good. "Any time an era ends for people who've graduated from a school, it leaves a void somewhat in their hearts," he said. "It's difficult." Copyright 2009 The Associated Press.