NOGALES, AZ - Authorities say they have discovered an incomplete smuggling tunnel along the U.S.-Mexico border in Nogales.
U.S. Customs and Border Protection says the unfinished tunnel was found this week during a joint effort by U.S. and Mexican authorities.
Officials say authorities noticed freshly disturbed dirt within the channel floor of a drainage system near a port of entry in Nogales.
They later discovered a tunnel that began in Mexico and extended 133 feet into the U.S., but it did not yet have an opening from the ground.
As U.S. border security has surged on land, drug cartels have turned to the sky, sea and tunneling beneath the ground to avoid detection.
More than 75 such underground passages have been found along the border since 2008, concentrated largely in California and Arizona.