What does a 'secure' border look like?

As apprehension numbers fell, home values skyrocketed. In 2001, an outlet mall opened right along the border. It now counts Brooks Brothers, Polo Ralph Lauren and Coach as tenants.

More than manpower helped to shut down the path into San Diego. An 18-foot-high steel mesh fence extending roughly 14 miles from the Pacific Ocean was completed in 2009, with razor wire topping about half of it. A dirt road traversing an area known as "Smugglers Gulch," which border agents had to navigate slowly, was transformed into a flatter, all-weather artery at a cost of $57 million.

This past year the Border Patrol's San Diego sector, which covers 60 miles of land border, made fewer arrests than in any year since 1968. Agents averaged 11 arrests each, a change that marvels veterans. Agents today may even pursue just one crosser over several shifts.

"I'm not going to say it's impossible, but it's a lot more difficult to cross the border here," said agency spokesman Steven Pitts.

After Gatekeeper, smugglers tried new tactics. They pelted agents with rocks, hoping to create an opening for a mad dash when other agents rushed to help. Or one group would jump the fence to draw agents' attention long enough for another to try its luck.

Now, other threats have emerged. U.S. authorities identified 210 human and drug smuggling attempts at sea during FY2012, up from 45 four years earlier. A Coast Guardsman died in December when a suspected smuggling vessel struck him.

And nearly all of more than 70 drug smuggling tunnels found along the border since October 2008 have been discovered in the clay-like soil of San Diego and Tijuana, some complete with hydraulic lifts and rail cars. They've produced some of the largest marijuana seizures in U.S. history.

Still, few attempt to cross what was once the nation's busiest corridor for illegal immigration. As he waited for breakfast at a Tijuana migrant shelter, Jose de Jesus Scott nodded toward a roommate who did. He was caught within seconds and badly injured his legs jumping the fence.

Scott, who crossed the border with relative ease until 2006, said he and a cousin tried a three-day mountain trek to San Diego in January and were caught twice. Scott, 31, was tempted to return to his wife and two young daughters near Guadalajara. But, with deep roots in suburban Los Angeles and cooking jobs that pay up to $1,200 a week, he will likely try the same route a third time.

"You need a lot of smarts and a lot of luck," he said. "Mostly luck.

"It's a new world."

EL PASO, Texas: Steel bars still up; crossings and crime down

Burglar bars still protect many a home in the Chihuahuita neighborhood near downtown El Paso, a reminder of a time when immigrant crossers would break in looking for food or trying to duck the Border Patrol. Carmen Silva recalls those days. At 90, she tells of migrants hiding under cars and in backyards. Now, she says: "Nobody comes through anymore."

Patricia Rayjosa has lived in the same neighborhood as Silva for the past 18 years. Once, she said, migrants crossed 30, 40, 50 at a time to overwhelm agents standing watch. Others swam across the Rio Grande or waded north on tire tubes.

"One morning, as I went out to feed my dogs, I found ... wire cutters. I didn't see them but I could tell they went across my backyard," said Rayjosa, 53. But she agrees with Silva's assessment. Now, "It's not easy to cross."

In the early 1990s, El Paso ran second to San Diego in the number of illegal immigrants coming north. Then, in 1993, the Border Patrol launched "Operation Hold the Line," the first of a series of enforcement actions intended to gain "operational control" of the Southwest border.