STEVE INSKEEP, host:
The Department of Homeland Security is attempting to lock down the southern border. Hundreds of miles of fence are going up along the frontier with Mexico. And over the last four years, the number of Border Patrol agents on the boundary has nearly doubled. Those measures have helped to sharply reduce the number of illegal immigrants crossing into the United States. As part of a series on the changing U.S.-Mexican border, NPR's Jason Beaubien recently spent a day with the Border Patrol in Nogales, Arizona.
JASON BEAUBIEN: The arid, khaki-colored hills surrounding Nogales, Arizona, look soft and rolling from a distance. But up close the terrain is menacing. Dry, waist-high grasses grab at your clothes. Thorny bushes scratch at your skin. The dusty soil gives way under your ankles.
It's just after sunrise, and Border Patrol agent Benny Rosario is leading three Mexican men in handcuffs out of the brush to a dirt road. Rosario says agents on a nearby hill with a night vision telescope spotted several groups of migrants moving through here in the pre-dawn darkness.
Agent BENNY ROSARIO (Border Patrol): It's mainly infrared traffic, so they pick up the heat spots. They can kind of gauge. You can see the terrain out here. It's pretty rough. You know, it's all hill over dale. And for the most part, they're able to accurately put the agents in on where the group might be going, so it's been working out for us tonight.
BEAUBIEN: It's been a busy night in the U.S. Border Patrol's busiest stomping ground. The Tucson sector covers 262 linear miles of the Arizona border from the Yuma County line to New Mexico. Last year, the Border Patrol here arrested more than 300,000 illegal migrants. The agents use walkie-talkies, remote cameras, ground sensors, radar systems, dogs, floodlights, night vision goggles, and just about anything else they can think of to catch people sneaking over the border. In the end, Agent Rosario says his job can come down to a foot race. Many of the migrants scatter when the Border Patrol descends on them.
Agent ROSARIO: Tonight, fortunately, it hasn't been that case. There was one group that was actually this group that ran from us initially, up further north, but we were able to - the scope trucks were able to stay on them. And we were able to pick them up further south here.
BEAUBIEN: The men he's just caught had been in the desert for three days. The first thing they ask for as they are being loaded into the back of a Border Patrol truck is water.
Agent ESMERALDA MARROQUIN (Supervisor, Border Patrol, Tucson Sector): Right now, we're in our communications center for the Border Patrol at the Nogales Station.
BEAUBIEN: Esmeralda Marroquin is a supervisor with the Border Patrol here. She's standing in what looks like a war room. Two radio dispatchers sit in front of a bank of video monitors.
Agent MARROQUIN: We have about 22 different cameras that we use. And they are all equipped, also, to see in the dark.
BEAUBIEN: The cameras are trained on various parts of the Nogales border. Some of the screens show the rusty old fence that cuts a swath between residential neighborhoods in Nogales, Arizona, and Nogales, Sonora. Other screens show the new fence on the outskirts of town and vehicle barriers in the desert. Across the border, hundreds, maybe even thousands of people are getting ready to test the Tucson sector agents. Carlos Gonzales is one of them. He was recently deported, and he's preparing to head right back in.
Mr. CARLOS GONZALES: Me and my friend, we're going to come back tonight. We're going to start walk about 11 o'clock when the immigration moves. That time, the immigration moves. So we get the chance to walk, walk. And we're going to walk two nights in the desert.
BEAUBIEN: The 28-year-old Gonzales has lived half his life in the States. He says he expects to die in New York City. If he's not careful, he could die here in the desert. Last year, at least 183 migrants lost their lives trying to cross this part of the Arizona border. Gonzales says he's not worried about all the Border Patrol's fancy new technology. If he's caught, he says, he'll just try again.
The terrain between Nogales, Sonora, and Nogales, Arizona, is such that rainwater flows north. One problem for the Border Patrol is that a massive flood control system runs from the Mexican side into the U.S. Agent Marroquin is standing in a tunnel that's big enough to drive a truck through.
Agent MARROQUIN: Unfortunately, people do cross. And a lot of people don't understand the dangers of these tunnels, and how quickly they can flood, and how quickly they can lose their life. Once it starts raining, it's a matter of minutes to get someone out of there before it flash floods, and then rescue efforts begin further north.
BEAUBIEN: The Border Patrol has installed cameras in the tunnel and nozzles that can fill the cavern with pepper spray if anyone tries to sneak through. In addition to the drainage tunnels, the Border Patrol discovered 14 homemade tunnels crossing the boundary in 2008. The tunnels are used to smuggle both migrants and drugs. Agents here seized more than 400 tons of marijuana last year as well as huge shipments of cocaine, methamphetamines, and heroin.
Mr. BRIAN LEVIN (Spokesman, U.S. Customs and Border Protection): We've seen it inside baby diapers. We've seen it inside prosthetic limbs. You name it, we've seen it at some point.
BEAUBIEN: Brian Levin with U.S. Customs and Border Protection is standing at the Nogales port of entry. Levin says some 45,000 people enter the U.S. through this port every day, and his officers process $18 billion worth of cargo each year.
Mr. LEVIN: We are the busiest port of entry for winter produce coming in from Mexico, heading to North America.
BEAUBIEN: Under the reorganized Department of Homeland Security, Customs and Border Protection is in charge of securing the legal ports of entry, the formal customs and immigration checkpoints into the U.S. Border Patrol is in charge of the rest of the border. Levin says at the port of entry, agents have to search for illegal migrants, narcotics, and other contraband, while still allowing legitimate traffic to flow.
Mr. LEVIN: We have to be able to balance our enforcement mission with our facilitation mission. We cannot sacrifice the safety and security of the United States for facilitation, but we're not going to ignore that. And again it comes down to balancing the two.
BEAUBIEN: Levin says new technology is helping to speed traffic and secure the border. Scanners can read chips in passports and IDs even before the drivers gets to the customs booth. Radiation detectors can screen for a dirty bomb. And computers link his agents to criminal databases in Washington. Yet despite all this technology at the port, smugglers still regularly cross in the open desert. About three miles outside of Nogales, Esmeralda Marroquin has just found a spot where vehicles have been driving over a small ridge to get around a new Border Patrol fence.
Agent MARROQUIN: This is a drive through. They've actually brought a car up and over, and are getting around the fencing here. As soon as areas like this are discovered, they're immediately addressed, and more fencing is put up to control it.
BEAUBIEN: Marroquin describes her work as a Border Patrol agent as an art that mixes tracking with technology and intuition. Agents regularly pursue groups of migrants just following footprints in the sand. The awkward hand gesture of a driver, she says, can tip you off that the trunk is full of drugs or illegal immigrants.
The additional personnel, the new fences, the added technology are all making the Arizona border a lot harder to cross. But ultimately, she says, it's the agents who are out there every day chasing people through the thorns and the rugged grasslands who have changed this frontier. Jason Beaubien, NPR News, Nogales, Arizona.
INSKEEP: Tomorrow, Jason moves a little further east along the border to Juarez. It is the twin city of El Paso, Texas, and it's being battered by a drug war and recession. For more on this series go to our Web site at npr.org.