U.S. Sen. Susan Collins says she would support locating a missile defense system in the Caribou-Limestone area of northern Maine. Defense Department officials said Friday they’re moving forward with plans for environmental impact studies on three potential sites for ballistic missile “interceptor” systems. Two are on the East Coast and one’s in the West. The Portland Press Herald says Collins’ office could not confirm whether Caribou or Limestone is on the list. But Collins, who is from Caribou and was the top Republican on the Senate Armed Services Committee until this year, indicated she would support locating a missile defense system in that area. Sites recommended in a report last year included the Caribou area and Fort Drum in upstate New York. Caribou’s near the former Loring Air Force Base in Limestone.