Since 1995 more than 90 illicit underground passageways have been discovered in various states of completion in the two-mile stretch of urban frontier that separates Nogales, Ariz., from its twin city on the Mexican side of the border. Twenty-two complete tunnels have been found in the past three years alone. The city has become infamous as the Tunnel Capital of the Southwest.

Pictured, the 10-inch-wide entrance to a smuggler’s tunnel uncovered in August 2011.

Since 1995 more than 90 illicit underground passageways have been discovered in various states of completion in the two-mile stretch of urban frontier that separates Nogales, Ariz., from its twin city on the Mexican side of the border. Twenty-two complete tunnels have been found in the past three years alone. The city has become infamous as the Tunnel Capital of the Southwest.

Pictured, the 10-inch-wide entrance to a smuggler’s tunnel uncovered in August 2011.

Nogales's Drug Tunnels

Tunnel Capital of the Southwest
Tunnel Capital of the Southwest

Since 1995 more than 90 illicit underground passageways have been discovered in various states of completion in the two-mile stretch of urban frontier that separates Nogales, Ariz., from its twin city on the Mexican side of the border. Twenty-two complete tunnels have been found in the past three years alone. The city has become infamous as the Tunnel Capital of the Southwest.

Pictured, the 10-inch-wide entrance to a smuggler’s tunnel uncovered in August 2011.

Kevin Hecht
Kevin Hecht

Border Patrol agent Kevin Hecht is “the tunnel guru,” says a former colleague. Hecht is one of the few who enter the small dirt tunnels.

Exit Up
Exit Up

An agent exits a popular smuggling route.

Tunnel Discovery
Tunnel Discovery

A drug tunnel that U.S. Customs discovered in Nogales, in a February 2001 photo.

Cocaine Bricks
Cocaine Bricks

Some of the drugs discovered by U.S. Customs in February 2001. In the home where the tunnel terminated, Customs agents found 198 bricks of cocaine weighing 840 pounds.

Tunnel Entrance
Tunnel Entrance

June 2007: As ICE and DEA agents uncover a tunnel entrance in a Nogales home, Sonoran State Police arrest five suspects at the tunnel’s other end.

Port of Entry
Port of Entry

Border Patrol agents Kevin Hecht, left, and David Jimarez at the U.S. and Mexico port of entry in Nogales on Sept. 30, 2010.

Under the Border
Under the Border

A smuggler's tunnel found in Nogales by the U.S. Border Patrol, in a May 2011 photo. The Border Patrol said the tunnel, which was fitted with lights, water pumps, and a ventilation system, ran 250 feet under the border at a depth of 15 feet.

‘Parking Meter’ Tunnel
‘Parking Meter’ Tunnel

August 2011: The “parking meter” tunnel to the San Enrique hotel in Mexico is found. A box truck at a parking spot in downtown Nogales covered a hole that opened into a tunnel that led across the border.

Drug Seizure
Drug Seizure

The August 2011 haul: 2,600 pounds of marijuana.

Under a Deck
Under a Deck

November 2011: Authorities find a tunnel under a deck at one home and, 15 days later, a second under the bedroom of a house down the block.

Cartel Profit
Cartel Profit

A 2010 Rand Corp. report estimated that the Mexican cartels’ drug operations turn a $6.6 billion profit every year.

Standing Room
Standing Room

Very few tunnels are big enough for agents to stand.

Tunnel Filling
Tunnel Filling

Once located, tunnels are filled with concrete.