( CNN ) -- Authorities have found a massive underground drug smuggling tunnel snaking through the U.S.-Mexican border , and law officers are marveling over its sophistication . The uncompleted tunnel measures 48 feet in the U.S. and 35 feet in Mexico . `` This is one of the most elaborate tunnels I 've seen , '' Border Patrol agent Michael Scioli said . Border Patrol agents found the uncompleted tunnel last week , the patrol said in a statement . Measuring 48 feet in the United States and 35 feet in Mexico , the tunnel contains side walls framed with 2-by-4 wooden studs and ceiling construction . `` It 's elegant in the sense it has electrical work wired into the Mexico side . It even has a hose for ventilation and lightning , '' Scioli said . The development points to successes law officers are having in uncovering the tunnels , with an additional 16 tunnels found since October 1 . But it also underscores the skills and savvy of the drug smuggling industry . A resident tipped off the patrol about construction activity through the wall of a building in Nogales , Arizona . Agents arrested two people cutting a hole .
48 feet of tunnel is in United States and 35 feet in Mexico . Officials said tunnel has ventilation , concrete , framed walls . Police reported suspicious construction in Phoenix , Arizona .