U.S. customs inspectors monitor a Union Pacific freight train carrying goods from Mexico as it crosses from Nogales, Sonora, Mexico, in to Nogales, Ar

U.S. customs inspectors monitor a Union Pacific freight train carrying goods from Mexico as it crosses from Nogales, Sonora, Mexico, in to Nogales, Arizona, USA, at the DeConcini Customs Inspection Station as part of NAFTA or the North American Free Trade Agreement.