Experts said many migrants used the routes to head straight for building jobs in places such as Central Florida. While the construction collapse dissuaded plenty of those workers from making the trip, so did the new wall.

''What the fence did was shift the activity from the urban area to the valleys where it is more dangerous, where they are killing each other and the migrants are prey for robbers,'' said Santa Cruz County Sheriff Tony Estrada. ``It moved them, that's all it did. It also created an industry where smugglers make big money. The individual who in the past could have made it through the desert on their own now has to hire a coyote.''

On that, even the Border Patrol agrees.

''If you don't have a coyote, you get caught like that,'' said the agency's Tucson sector spokesman Michael Scioli, snapping his fingers.

More migrants are using underground tunnels built largely by drug traffickers to sneak if not over the border, then under it. In 2008, the agency discovered 14 such passages, including one just feet from the main Tucson-Mexico border crossing station. One of the tunnels ended in a U.S. federal employee parking lot.

''Before Osama, I used to cross no problem,'' said Julio César Vega Torres, who was recently deported back to Mexico after more than a decade in Los Angeles. ``It's too hard to cross now. They have more security. The border patrol is doing a good job.''

Vega is a vagrant now in the Mexican border town of Nogales, where he spends his days scheming ways to get back to California.

He knows the enforcement numbers are against him.

Ten years ago, there were just 600 agents patrolling this portion of the Arizona border. Now, there are 3,100. The agency expects to have 18,000 Border Patrol agents nationwide by the end of the year, double the number employed when President George W. Bush first took office.

Many Mexicans who work on the border said they hoped immigration would pick up again after President-elect Barack Obama takes office. Obama has said he is committed to enforcing border security, but in Mexico, many people who depend on immigration are hoping he will create a guest worker program or at least more jobs.

University of Arizona immigration expert Judith Gans said Janet Napolitano, Obama's nominee to lead the Department of Homeland Security, understands the complexities and realities of trying to seal the border while economic forces create the need for low-skilled labor. As the governor of Arizona, Napolitano signed an employee sanctions law, but vetoed other punitive anti-immigrant measures, Gans said.

''She has been reasonably moderate and certainly understands the challenges,'' Gans said. 'She's been famously quoted saying, `Show me a 50-foot wall, and I'll show you a 50-foot ladder.' ''

The U.S. Border Patrol acknowledges that the wall is essentially a ''speed bump'' in the desert, but said the multi-faceted approach has worked.

''If there has been a decrease in migration, it's because of three things: Increased manpower, technology and infrastructure,'' said Scioli, the Border Patrol spokesman. ``We have 80 cameras, towers and lights and sensors on the ground that pick up movement. We have aerial vehicles, remote control aircraft doing surveillance. There's radar that picks up heat and sends GPS coordinates. What we had to do in the past was look for signals in the sand.''

Marco Antonio Martínez, mayor of Nogales, Mexico, said border enforcement has toughened so much that migrants who get through have to try a third and fourth time.

''The people in Cuba do not stop coming despite the sharks and the people in East Berlin did not stop coming despite the rifles,'' he said. ``The Mexicans will not stop coming until this dramatic contrast in economies ends.''

Not even the government's new program to criminally prosecute migrants caught crossing will stop them, he said.

MIGRANTS CHARGED

The U.S. government recently launched Operation Arizona Denial Prosecution Initiative, a plan to criminally charge 60 randomly selected migrants every day. Judges argue that it is clogging up the federal court system better suited for other purposes.

''If I get caught, so what. I would only have to serve a little time,'' said Eduardo Flores, 17, who was in Altar, Mexico getting ready to leave.

Rosaber Pérez, a farm worker from Chiapas, said there just is not enough work in his home town, so he spent a few days recently at a ramshackle guest house in the town of Altar, 60 miles south of the border, while he prepared to cross.

''You have to risk it -- you have to risk your life,'' Pérez said. ``The situation at home for me and my four kids keeps getting worse. We can't live in Chiapas anymore. It's going to be hard, but you have to try.

``I am going to Florida.''

Join the discussion

The Miami Herald is pleased to provide this opportunity to share information, experiences and observations about what's in the news. Some of the comments may be reprinted elsewhere in the site or in the newspaper. We encourage lively, open debate on the issues of the day, and ask that you refrain from profanity, hate speech, personal comments and remarks that are off point. In order to post comments, you must be a registered user of MiamiHerald.com. Your username will show along with the comments you post. Thank you for taking the time to offer your thoughts.

     Showing: Oldest first Newest first Most-recommended first Least-recommended first

@Nyx.AuthorDisplayName@ wrote on @Nyx.PostedAtTime@:

@Nyx.repliedToText@

@Nyx.replyAnswerText@

Reply to this Comment @Nyx.Recommender@ @Nyx.AbuseReporter@