Once, the barren mesas and shrub-covered canyons that extend east of the Pacific Ocean held the most popular routes for illegal immigrants heading into the U.S.
Dozens at a time sprinted to waiting cars or a trolley stop in San Diego, passing border agents who were too busy herding others to give pause.
Now, 20 years after that onslaught, crossing would mean scaling two fences (one topped with coiled razor wire), passing a phalanx of agents and eluding cameras positioned to capture every incursion.
The difference, Homeland Security Secretary Janet Napolitano said on a recent tour, is like "a rocket ship and a horse and buggy."
In pure numbers it is this: Where border agents made some 530,000 arrests in San Diego in fiscal year 1993, they had fewer than 30,000 in 2012.
There is no simple yardstick to measure border security. And yet, as the debate over immigration reform ramps back up, many will try.
"Secure the border first" has become not just a popular mantra whenever talk turns to reform but a litmus test for many upon which a broader overhaul is contingent.
"We need a responsible, permanent solution" to illegal immigration, U.S. Sen. Marco Rubio, the Florida Republican who is working to develop a reform plan, said in his State of the Union response this month. "But first," he added, "we must follow through on the broken promises of the past to secure our borders and enforce our laws."
In fact, the 1,954-mile border with Mexico is more difficult to breach than ever. San Diego is but one example.
Two decades ago, fewer than 4,000 Border Patrol agents manned the entire Southwest border. Today there are 18,500. Some 651 miles of fence have been built, most of that since 2005.
Apprehensions, meantime, have plummeted to levels not seen since the early 1970s - with 356,873 in FY2012. Compare that to 1.2 million apprehensions in 1993, when new strategies began bringing officers and technology to border communities in California, Texas, New Mexico and Arizona. Now sensors have been planted, cameras erected, and drones monitor the borderlands from above.
But for those who live and work in communities along the international boundary, "secure" means different things. In Arizona, ranchers scoff at the idea. In New Mexico, locals worry about what's heading south in addition to flowing north. And in Texas, residents firmly believe that reform itself would finally help steady the flow of people and drugs.
These places have been transformed. Sealed? No. But as one border mayor asked: "How secure is secure?"
SAN DIEGO: From "banzai runs" to Brooks Brothers
Don McDermott spent most of his 21 years in the Border Patrol working the San Diego sector. He remembers the "banzai runs," when hordes of immigrants would storm inspection booths at one international crossing, scattering as they ran past startled motorists.
Back then, migrants crossed with audacity - even played soccer on U.S. soil as vendors hawked tamales and tacos. The "soccer field" was too dangerous to patrol, so agents positioned themselves a half-mile out, waiting for nightfall when groups would make a run for freedom.
"Hopefully you would catch more people that you saw going past you," said McDermott, who retired in 2008. "You caught who you could and knew they would be back before the night was over."
The tide turned when the U.S. government launched "Operation Gatekeeper" in 1994, modeled on a crackdown the previous year in El Paso, Texas. The effort brought 1,000 additional agents to San Diego. They parked their trucks against a rusting 8-foot-high fence made of Army surplus landing mats, and refused to yield an inch. They called it "marking the X."
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.
It was a shift in strategy from apprehending migrants already in the U.S. to preventing entry in the first place, and the effect was almost immediate: Within months, illegal crossings in El Paso went from up to 10,000 a day to 500, according to a Government Accountability Office report in 1994 called "BORDER CONTROL:
Revised Strategy Is Showing Some Positive Results."
Burglaries in neighborhoods like Chihuahuita decreased. Car thefts went down. And, as happened later in San Diego, apprehensions plunged: from nearly 286,000 in 1993 to about 9,700 last fiscal year in the El Paso Border Patrol sector, which encompasses 268 miles from West Texas across New Mexico. (Border Patrol staffing in the sector went from 608 agents in 1993 to more than 2,700 today.)
To El Paso Mayor John Cook, hinging reform to continued calls for a "secure border" seems absurd given the changes in his city.
"It is as secure as it has ever been. How secure is secure?" he said. "Some people who come with these ideas have no idea.
"I wish they would come down here and see."
But you don't have to drive too far into the New Mexico desert to see problems.
Marcus Martinez, the police chief in Lordsburg, N.M., recalled an incident in January where a local hotel manager stepped out to have a cigarette and saw a convoy of vehicles speeding through town. Four cars were eventually stopped - 80 miles north of the border - and 6 tons of marijuana were seized.
Patrick Green of the Hidalgo County Sheriff's Office in Lordsburg, said northbound traffic is only part of the problem. Even as people and drugs are smuggled north, guns and money are flowing back south. He deals with constant reports by homeowners and ranchers about break-ins.
The area has seen a huge influx of Border Patrol agents, but officers like Green fear the government will always be behind the curve in dealing with sophisticated smuggling operations.
"If the Border Patrol puts more people in the ground, they will take to the mountains," Green said. "We are always playing catch up."
MCALLEN, Texas: In bicultural region, residents root for reform as the path to "secure"
Some 800 miles southeast of El Paso is the Rio Grande Valley, where rapid growth has overtaken sugar cane and cotton fields and sleepy hamlets are now thriving cities. More than 1.2 million people live in the two border counties on the U.S. side of this southernmost tip of Texas, and a similar number are directly across the border anchored by the sprawling cities of Matamoros and Reynosa.
Here, illegal crossers can quickly slip into communities without being forced to trek for days through wide-open spaces.
Part of the solution was the border fence, and 400 landowners - most of them in this part of Texas - had property seized to build it. The fence divided people from swaths of their own land, but also struck many as an offensive gesture in this bicultural, bilingual region that views itself as one community with its Mexican sister cities.
More effective, locals said, has been the influx of Border Patrol agents - 2,546 in the Rio Grande Valley today, almost seven times more than 20 years ago.
And while some agents still patrol on horseback, others are aided now by night-vision goggles and unmanned Predator drones watching from 19,000 feet overhead with high-powered infrared cameras.
Definitions of a secure border vary here, but there's agreement that the premise should not stand in the way of immigration reform.
Tony Garza remembers watching the flow of pedestrian traffic between Brownsville and Matamoros from his father's filling station just steps from the international bridge. He recalls migrant workers crossing the fairway on the 11th hole of a golf course - northbound in the morning, southbound in the afternoon. And during an annual celebration between the sister cities, no one was asked for their papers at the bridge. People were just expected to go home.
Garza, a Republican who served as the U.S. ambassador to Mexico from 2002 to 2009, said it's easy to become nostalgic for those times, but he reminds himself that he grew up in a border town of fewer than 50,000 people that has grown into a city of more than 200,000.
The border here is more secure for the massive investment in recent years but feels less safe because the crime has changed, he said. Some of that has to do with transnational criminal organizations in Mexico and some of it is just the crime of a larger city.
Reform, he said, "would allow you to focus your resources on those activities that truly make the border less safe today."
Monica Weisberg-Stewart was born and raised an hour upriver in McAllen. Her father ran a store downtown that she runs today, filled with socks, underwear and jewelry. She echoes Garza's assessment that things feel less safe now but says that has more to do with the area's growth than with what's happening in Mexico.
"I thought that this was definitely the best place to raise my family," she said, "and I still believe that to be true today."
Hidalgo County Sheriff Lupe Trevino points out that drug, gun and human smuggling is nothing new to the border. The difference is the attention that the drug-related violence in Mexico has drawn to the region in recent years.
He insists his county, which includes McAllen, is safe. The crime rate is falling, and illegal immigrants account for small numbers in his jail. But asked if the border is "secure," Trevino doesn't hesitate. "Absolutely not."
"When you're busting human trafficking stash houses with 60 to 100 people that are stashed in a two, three-bedroom home for weeks at a time, how can you say you've secured the border?" he said.
Trevino's view, however, is that those people might not be there if they had a legal path to work in the U.S.
"Immigration reform is the first thing we have to accomplish before we can say that we have secured the border," he said.
NOGALES, Ariz.: In nation's busiest illegal corridor, ranchers scoff at "secure"
Everywhere he goes on his cattle ranch, Jim Chilton has a gun at the ready. He has guns at his front door, guns in his pickup truck, guns on his horse's saddle. His fear?
Coming across a bandit or a smuggler on his land northwest of Nogales, Ariz.
Cattleman Gary Thrasher frequently encounters immigrants and smugglers running through his property. Some have showered in his barn. He and his family live in constant dread.
"They really have secured the towns right along the border, but what that does is it drives all the traffic out into the rural areas around here," said Thrasher, a rancher and veterinarian for more than 40 years on the border east of Douglas, Ariz. "It sends the traffic right into our backyards."
The question of border security hits close to home to those who work the land in southern Arizona. It was here, in 2010, that cattle rancher Robert Krentz was gunned down while checking water lines on his property near Douglas. Local authorities have said they believe the killer was involved in smuggling either humans or drugs.
That same year, Border Patrol agent Brian Terry was killed in a shootout near Nogales with Mexican gunmen that brought attention to the federal government's botched weapons-trafficking probe called "Fast and Furious."
"The border is not secure," said Chilton. "Period. Exclamation mark."
Defining "secure border" in Arizona is never easy. Just last week, U.S. Sen. John McCain hosted two town hall meetings on immigration reform in his home state, and was left defending a plan he's been developing.
During a heated gathering in the Phoenix suburb of Sun Lakes, one man yelled that only guns would discourage illegal immigration. Another man complained that illegal immigrants should never be able to become citizens or vote. A third man said illegal immigrants were illiterate invaders who wanted free government benefits.
McCain urged compassion. "We are a Judeo-Christian nation," he said.
The crackdowns in Texas and California in the 1990s turned Arizona's border into the busiest for human smuggling for 15 years running now.
In 2000, agents in the Tucson sector made more than 616,000 apprehensions - a near all-time high for any Border Patrol sector. The number eventually began dipping as the agency hired more than 1,000 new agents and the economy collapsed. State crackdowns such as the "show me your papers" law - requiring police enforcing other laws to question the immigration status of those they suspect are in the country illegally - are also thought to have driven migrants away.
The result: the sector had 120,000 apprehensions in fiscal 2012.
But the amount of drugs seized in Arizona has soared at the same time. Agents confiscated more than 1 million pounds of marijuana in the Tucson sector last year, more than double the amount seized in 2005.
In Nogales, Sheriff Tony Estrada has a unique perspective on both border security and more comprehensive immigration reform. Born in Nogales, Mexico, Estrada grew up in Nogales, Ariz., after migrating to the U.S. with his parents. He has served as a lawman in the community since 1966.
He blames border security issues not only on the cartels but on the American demand for drugs. Until that wanes, he said, nothing will change. And securing the border, he added, must be a constant, ever-changing effort that blends security and political support - because the effort will never end.
"The drugs are going to keep coming. The people are going to keep coming. The only thing you can do is contain it as much as possible.
"I say the border is as safe and secure as it can be, but I think people are asking for us to seal the border, and that's unrealistic," he said.
Asked why, he said simply: "That's the nature of the border."